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In a monogamous culture, 100% of the adults are married. The average
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Updated on: 09 Oct 2018, 06:37
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In a monogamous culture, 100% of the adults are married. The average number of children per family is five and overpopulation is a threat. Programs to encourage birthcontrol have been ineffective. It has been suggested that this failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son. It is proposed that couples be encouraged to use birthcontrol measures after the birth of their first son. If this proposal is widely accepted in the culture, we may expect that: (A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females. (B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present. (C) the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females. (D) there will be no significant effect either on population growth or on gender balance. (E) the population will decline precipitously, because approximately half of all families will have only a single child.
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Originally posted by clubzzang on 23 Jun 2008, 21:05.
Last edited by Bunuel on 09 Oct 2018, 06:37, edited 1 time in total.
Edited the question.




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Re: In a monogamous culture, 100% of the adults are married. The average
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12 Jan 2017, 07:18
mbaprep2016 wrote: Hi sayantanc2k as per my understanding ...first two premise "all adults are married" and "avg number is 5" tells nothing about male to female ration currently. now with successful birth control ,we have two scenarios 1. first child is male child and birth control measures are taken(male:female gets higher) 2. first child is not male child and let us say 4 female and one male(female:male is higher) B tells the gender balance in future generations will remain as it is at present. please explain the same. Let us consider a simplified mathematical model: The society consists of 16 families: After 1st round of reproduction: 8 male + 8 female The families which have a male child stops reproducing. So other 8 families reproduce in the second round  of them 4 male and 4 female are born. After 2nd round of reproduction: 12 male + 12 female Similarly after 3rd round: 14 male + 14 female After, 4th round 15 male and 15 female. Now this mental experiment can be generalized with n number of families, and it will be seen that after mth round of reproduction, the number of male and female will be same = n/2 + n/4 +... upto m terms. Moreover as time passes (m increases), the rate at which the increase in no. of child happens goes on decreasing. ( 1st round: increased by 16(n), second round: increased by 8(n/2), 3rd round: increased by (n/4) and so on. Therefore answer B is correct.




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Re: In a monogamous culture, 100% of the adults are married. The average
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23 Jun 2008, 21:34
lets put some quants in this ...
lets assume probability of a birth of a male or female child is same 1/2.... So if the program is effective there'll be parents who'll stop at 1st, 2nd, 3rd ..... child, so the rate of population grwith will go down ... option C and D are out
even if half of the familes will have only one child, there'll be familes with more than 2 children also ... so option E is also out.
between A and B, I'd go for B, it wont effect the balance ...... Suppose there are 16 familes, so with a probability of 1/2, the birth of M and F child will have a pettern like this
First birth : 8M 8F Second birth : 4M, 4F (only with F in first round will go for second) Third birth : 2M, 2F (same logic as above) Forth birts : 1M, 1F
Total M = Total F = 15 ... so there will be a balance......
Answer B




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Re: In a monogamous culture, 100% of the adults are married. The average
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23 Jun 2008, 21:17
clubzzang ur on a roll... one good question after the other...
+1 for this one too
Althouh Im not too sure, I would answer B for this...
As it is every parents wants atleast one son. Currently,they dont adopt birth control measures to have a son..
If one has to adopt birth control measures after they have a son.. the gender balance essentially remains the same, but the population may dwindle, as people adopt birth control measures after their first son..



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Re: In a monogamous culture, 100% of the adults are married. The average
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24 Jun 2008, 11:56
proposal will cutdown the population
C,D are out
Population will dont decrease rapidly. E is out
A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females.
B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present.
Unable to decide between A and B
assume there are 10 families trying to have a baby.say 6 families give birth to girls m f 1st 4 6 the 3 families continue to try for a son say 3 families give birth to girls 2nd try 3 3 the 3 families continue to try for a son say 3 families give birth to girls 3rd try 0 3 the 3 families continue to try for a son say 3 families give birth to girls
4th try 0 3
Iam inclining towards A



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Re: In a monogamous culture, 100% of the adults are married. The average
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24 Jun 2008, 12:12
Great CR, clubzzang! +1 I was leaning towards E on a quick glance, but now I'm leaning more towards B We will have two types of families: 1) Those who get a boy first (stop at 1 boy) 2) Those who get a girl first, then stop at the 1st boy after that Assuming a 50/50 chance of getting a boy in the first place, we must assume that 50% of all the families will just have one boy. The other 50% will have 1+ girls and a boy I don't see how the number of girls will be higher in the long run, hence I'm going for B. Although I must admit there are quite a few assumptions that should be made for this question (I hope I don't see a similar one on the actual GMAT!) Other answers are clearly explained before my post. Can you confirm which is the OA?
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Re: In a monogamous culture, 100% of the adults are married. The average
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24 Jun 2008, 18:45
clubzzang wrote: In a monogamous culture, 100% of the adults are married. The average number of children per family is five and overpopulation is a threat. Programs to encourage birthcontrol have been ineffective. It has been suggested that this failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son. It is proposed that couples be encouraged to use birthcontrol measures after the birth of their first son.
If this proposal is widely accepted in the culture, we may expect that:
A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females.
B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present.
C) the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females.
D) there will be no significant effect either on population growth or on gender balance.
E) the population will decline precipitously, because approximately half of all families will have only a single child. IMO (C) is correct.



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Re: In a monogamous culture, 100% of the adults are married. The average
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24 Jun 2008, 19:43
aviator83 wrote: IMO (C) is correct.
C can't be correct IMO...Think of it this way: 50% chance of getting a boy, 50% chance of getting a girl. Two types of families. Those that get a boy first, and those that get a girl first: If boy (50% chance), then take contraceptives (1 boy in family, no more reproduction after that) If girl (50% chance), try again for boy. Most likely conclusion is 1 girl 1 boy (25%), slightly less likely is 2 girls 1 boy (12.5%), highly unlikely (6.25%) is 3 girls 1 boy. Most likely result is: Half all families will be 1boy only Other half will be split predominantly "1 girl and 1 boy", with a portion being "2 girls 1 boy" and a much smaller portion being "3 girls 1 boy" and other even more unlikely divisions. Overall the growth rate will slow down because now contraceptives will be adopted after the first son is born (as opposed to before when this was not actively encouraged) Gender balance should remain about the same since the "power in numbers of boys" judging by the 50% of families with 1 boy only plus the 25% of families with 1 girl and 1 boy, will be somewhat driven down by the various other probabilities of "2 girls 1 boy, 3 girls 1 boy, etc..." Hence, B I hope this clarifies it... Its quite complicated for a CR :S Most likely is that growth rate will go down and the gender balance will remain the same
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Re: In a monogamous culture, 100% of the adults are married. The average
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16 Jul 2010, 06:03
GMATobliterator wrote: aviator83 wrote: IMO (C) is correct.
C can't be correct IMO...Think of it this way: 50% chance of getting a boy, 50% chance of getting a girl. Two types of families. Those that get a boy first, and those that get a girl first: If boy (50% chance), then take contraceptives (1 boy in family, no more reproduction after that) If girl (50% chance), try again for boy. Most likely conclusion is 1 girl 1 boy (25%), slightly less likely is 2 girls 1 boy (12.5%), highly unlikely (6.25%) is 3 girls 1 boy. Most likely result is: Half all families will be 1boy only Other half will be split predominantly "1 girl and 1 boy", with a portion being "2 girls 1 boy" and a much smaller portion being "3 girls 1 boy" and other even more unlikely divisions. Overall the growth rate will slow down because now contraceptives will be adopted after the first son is born (as opposed to before when this was not actively encouraged) Gender balance should remain about the same since the "power in numbers of boys" judging by the 50% of families with 1 boy only plus the 25% of families with 1 girl and 1 boy, will be somewhat driven down by the various other probabilities of "2 girls 1 boy, 3 girls 1 boy, etc..." Hence, B I hope this clarifies it... Its quite complicated for a CR :S Most likely is that growth rate will go down and the gender balance will remain the same gud eg by GMATobliterator bt not a convincing explanation. I think it is quite illogical 2 say that Gender balance should remain about the same. It u dig down deep in your eg u will find that there is a possibility that future generations (might) contain a disproportionately high number of females. both A and B are very close.
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Re: In a monogamous culture, 100% of the adults are married. The average
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16 Jul 2010, 10:49
I chose D ; if we assume that in the earlier case  the families didnt expand after getting their first male child  nothign changes after institituing the law as well. The only difference is ppl stop reproducing after getting frst male child. How is it different from what was happening earlier  unless it can be shown to be otherwise in which case I can agree that population growth rate may decrease.



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Re: In a monogamous culture, 100% of the adults are married. The average
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18 Jul 2010, 06:04
dwivedys wrote: I chose D ; if we assume that in the earlier case  the families didnt expand after getting their first male child  nothign changes after institituing the law as well. The only difference is ppl stop reproducing after getting frst male child. How is it different from what was happening earlier  unless it can be shown to be otherwise in which case I can agree that population growth rate may decrease. That was exactly how I interpreted it, initially. However, the question specifically says " if this proposal is widely accepted in the culture". To choose D is to assume that the proposal is not accepted. Very good question.



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Re: In a monogamous culture, 100% of the adults are married. The average
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21 Jul 2010, 07:50
I will go with B although i am not convinced that there WILL be gender balance. Simply because birth is a natural occurrence. Many factors such as birth mortality and trans gender births need to be taken into account when determining the gender balance.
My reasoning is
C and D are out because rate of increase will NOT SLOW DOWN E is out because population will not decline precipitously
between A and B. A is out because there absolutely no way to conclude that future generations will have disproportionately high number of females
I would have chosen A if it mentioned "the rate of population increase will be slowed, and the gender balance in future generations will not remain as it is at present
Only B survives the POE



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Re: In a monogamous culture, 100% of the adults are married. The average
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17 Mar 2014, 10:01
After the proposal is implemented, the probabilities of getting a male or female child do not change. Till the first male is born, the same number of children before it would have been male, before or after the proposal is implemented. After the first male is born, before the proposal was implemented, there was an equal chance of getting a boy child or a girl child. After the proposal is implemented, there are no more births, so no skewing of the probability ratios occurs.
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Re: In a monogamous culture, 100% of the adults are married. The average
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23 Sep 2015, 03:25
The average number of children per family is five. Failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son.
Proposal: couples be encouraged to use birthcontrol measures after the birth of their first son.
If this proposal is widely accepted in the culture, we may expect that: (Application question......if x plan is applied then what can happen.....)
We have two scenarios 1. first child is male child and birth control measures are taken(male:female gets higher) 2. first child is not male child and let us say 4 female and one male(female:male is higher)
this will ensure that rate of population increase will be slowed, but gender imbalance will remain.
A. the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females. (high no of females is possible as per case 2 but not case 1)
B. the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present. (This is possible in all circumstances of both cases 1 & 2)
C. the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females. (high no of females is possible as per case 2 but not case 1 and rate will not remain same)
D. there will be no significant effect either on population growth or on gender balance. (This cannot be true in any case)
E. the population will decline precipitously, because approximately half of all families will have only a single child. (there is no guarantee that approx half will have single male child)



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Re: In a monogamous culture, 100% of the adults are married. The average
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12 Jan 2017, 01:41
Hi sayantanc2k as per my understanding ...first two premise "all adults are married" and "avg number is 5" tells nothing about male to female ration currently. now with successful birth control ,we have two scenarios 1. first child is male child and birth control measures are taken(male:female gets higher) 2. first child is not male child and let us say 4 female and one male(female:male is higher) B tells the gender balance in future generations will remain as it is at present. please explain the same.



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Re: In a monogamous culture, 100% of the adults are married. The average
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12 Jan 2017, 10:30
sayantanc2k wrote: mbaprep2016 wrote: Hi sayantanc2k as per my understanding ...first two premise "all adults are married" and "avg number is 5" tells nothing about male to female ration currently. now with successful birth control ,we have two scenarios 1. first child is male child and birth control measures are taken(male:female gets higher) 2. first child is not male child and let us say 4 female and one male(female:male is higher) B tells the gender balance in future generations will remain as it is at present. please explain the same. Let us consider a simplified mathematical model: The society consists of 16 families: After 1st round of reproduction: 8 male + 8 female The families which have a male child stops reproducing. So other 8 families reproduce in the second round  of them 4 male and 4 female are born. After 2nd round of reproduction: 12 male + 12 female Similarly after 3rd round: 14 male + 14 female After, 4th round 15 male and 15 female. Now this mental experiment can be generalized with n number of families, and it will be seen that after mth round of reproduction, the number of male and female will be same = n/2 + n/4 +... upto m terms. Moreover as time passes (m increases), the rate at which the increase in no. of child happens goes on decreasing. ( 1st round: increased by 16(n), second round: increased by 8(n/2), 3rd round: increased by (n/4) and so on. Therefore answer B is correct. I apologies I am still confused , you stared with equal ratio lets say 16 families After 1st round of reproduction: 10 male + 6 female The families which have a male child stops reproducing. So other 6 families reproduce in the second round  and have 6 male. now ratio will 16 + 6 I am sure I am missing something very important



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Re: In a monogamous culture, 100% of the adults are married. The average
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14 Jan 2017, 07:21
mbaprep2016 wrote: sayantanc2k wrote: mbaprep2016 wrote: Hi sayantanc2k as per my understanding ...first two premise "all adults are married" and "avg number is 5" tells nothing about male to female ration currently. now with successful birth control ,we have two scenarios 1. first child is male child and birth control measures are taken(male:female gets higher) 2. first child is not male child and let us say 4 female and one male(female:male is higher) B tells the gender balance in future generations will remain as it is at present. please explain the same. Let us consider a simplified mathematical model: The society consists of 16 families: After 1st round of reproduction: 8 male + 8 female The families which have a male child stops reproducing. So other 8 families reproduce in the second round  of them 4 male and 4 female are born. After 2nd round of reproduction: 12 male + 12 female Similarly after 3rd round: 14 male + 14 female After, 4th round 15 male and 15 female. Now this mental experiment can be generalized with n number of families, and it will be seen that after mth round of reproduction, the number of male and female will be same = n/2 + n/4 +... upto m terms. Moreover as time passes (m increases), the rate at which the increase in no. of child happens goes on decreasing. ( 1st round: increased by 16(n), second round: increased by 8(n/2), 3rd round: increased by (n/4) and so on. Therefore answer B is correct. I apologies I am still confused , you stared with equal ratio lets say 16 families After 1st round of reproduction: 10 male + 6 female The families which have a male child stops reproducing. So other 6 families reproduce in the second round  and have 6 male. now ratio will 16 + 6 I am sure I am missing something very important The assumption is that the probability of getting a male child and that of getting a female child is 1:1. So when 16 families reproduce, 8 males and 8 females are born. Now read the above post. (I did not quite understand how you got 10 males and 6 females after 1st round) If you still have doubt, please post again.



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Re: In a monogamous culture, 100% of the adults are married. The average
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27 Mar 2017, 05:33
Earlier Tradition : Male children very highly valued. New Proposal: Couples be encouraged to use birthcontrol measures after the birth of their first son. If this proposal is widely accepted in the culture, we may expect that: A. the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females. How do we know females would be high? It could men who are very high in number. So, Incorrect.B. the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present. : Correct. C. the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females. : No, population growth will obviously change.D. there will be no significant effect either on population growth or on gender balance. : Really? I don't think so.E. the population will decline precipitously, because approximately half of all families will have only a single child. :How can we say Half will have only a single child? Too extreme to consider.
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Re: In a monogamous culture, 100% of the adults are married. The average
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30 Sep 2018, 08:50
Hi, I am still not understanding the reason how gender balance will remain the same, lets see some possibilities Case 1 : First kid Boy. Stop. Case 2 : First kid girl, second kid boy. Stop. Case 3 : First kid girl, second kid girl, third kid boy. Stop. Case 4 : 3 girls, then a boy. Can't this go on? How are we sure that gender balance will be maintained? Where am I going wrong?
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