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A software programmer does 20% of the work in 80% of the
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Updated on: 05 Nov 2012, 22:27
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A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, How many lines of code were written in the last two weeks, in terms of X? A. 13x /15 B. 15x/15 C. 7x/15 D. 2x/30 E. 13x/30
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Originally posted by vivatran on 06 Mar 2011, 05:42.
Last edited by vivatran on 05 Nov 2012, 22:27, edited 3 times in total.




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Re: Work Problems
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15 Sep 2011, 22:27
shuwa wrote: A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, How many lines of code were written in the last two weeks, in terms of X?
A) 13x /15
B) 15x/15
C) 7x/15
D) 2x/30
E) 13x/30 Another thing you might want to note here is that he does 80% of the work in the last 20% of time i.e. in last 6 days. So the work he does in last 14 days is more than 4X/5 but less than X. Only option (A) lies in this range.
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Re: Work Problems
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06 Mar 2011, 05:54
30 days X lines 80% of 30 24 days; 0.2X lines Remaining 6 days: 0.8X lines Need to find out for last 14 days; We know the number of lines for last 6 days: 0.8X How about 8 days before that; 24 days 0.2X 1 day  0.2X/24 lines 8 days  (0.2X/24)*8 lines = (1/15)X lines Total number of lines in last 14 days (1/15)x + 0.8X = (1/15)x + (8/10)X = (52/60)X = (13/15)X lines of codes
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Re: Work Problems
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06 Mar 2011, 06:35
shuwa wrote: A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, How many lines of code were written in the last two weeks, in terms of X?
Please explain. thanks It's better to plug the numbers for this question let x=30 lines; 20% of the work in 80% of the time > 0.2*30 lines=6 lines in the first 0.8*30 days=24 days and the remaining 24 lines in last 6 days; Last 14 days = last 6 days (stage 2) + previous 8 days (part of stage 1): 24 lines in last 6 days + 1/3*6=2 lines in previous 8 days (as 8 is 1/3 of 24 days in stage 1) = 26 lines in the last 14 days, which is 26/30=13/15 part of the whole job. P.S. Please provide answer choices for PS problems.
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Re: Work Problems
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18 Sep 2011, 10:16
work  time
1 t 20/100 80t/100 80/100 20t/100
task
30 days  x lines
20x/100 will be finished in (80/100)*30 days ( i.e 24 days)
80x/100 in (20/100)*30 days (i.e 6 days)
work done in last two weeks = last 6 days work + last 8 days work
= 80x/100 + (20x/100)(8/24) = 13x/15
(one flaw i see in the question is that it does not say the programmer works initial 20% of work in 80% time. so if you take it as initial 80% of work in 20% time, answer would be different)



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Re: Work Problems
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18 Sep 2011, 21:06
Spidy001 wrote: (one flaw i see in the question is that it does not say the programmer works initial 20% of work in 80% time. so if you take it as initial 80% of work in 20% time, answer would be different)
I did notice the same thing and therefore, read the question stem carefully. Notice that it says 'does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time.' Important is the use of the word 'remaining' which implies that he does 20% of the work in the first 80% of time and 80% in the leftover 20% time. Therefore, the intent of the question is quite clear.
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Re: Work Problems
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21 Sep 2011, 20:10
Hi, I'm trying to plug in for Question # 138 in OG 12. Could anyone point out where i'm going wrong in my reasoning? No. of Boxes loaded by Night workers = 3/4 of Day workers No. of Night workers = 4/5 of Day workers. Let the number of Day workers = 100 and they load a total of 100 boxes. No. of boxes loaded by Night workers = 3/4 x 100 = 75 No. of Night workers = 4/5 x 100 = 80 total no. of boxes loaded by both workers = 175 total no. of boxes loaded by day workers = 100 fraction of boxes loaded by day workers out of the total = 100/175 = 4/7 The closest answer is 4/5 which is D. But the correct answer is 5/8 which is E.



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Re: Work Problems
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22 Sep 2011, 20:51
gmatyro wrote: Hi, I'm trying to plug in for Question # 138 in OG 12. Could anyone point out where i'm going wrong in my reasoning? No. of Boxes loaded by Night workers = 3/4 of Day workers No. of Night workers = 4/5 of Day workers. Let the number of Day workers = 100 and they load a total of 100 boxes. No. of boxes loaded by Night workers = 3/4 x 100 = 75 No. of Night workers = 4/5 x 100 = 80 total no. of boxes loaded by both workers = 175 total no. of boxes loaded by day workers = 100 fraction of boxes loaded by day workers out of the total = 100/175 = 4/7 The closest answer is 4/5 which is D. But the correct answer is 5/8 which is E. You need to make a new thread for a new question, put down the question and your method.
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Re: Work Problems
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23 Sep 2011, 13:19
VeritasPrepKarishma wrote: gmatyro wrote: Hi, I'm trying to plug in for Question # 138 in OG 12. Could anyone point out where i'm going wrong in my reasoning? No. of Boxes loaded by Night workers = 3/4 of Day workers No. of Night workers = 4/5 of Day workers. Let the number of Day workers = 100 and they load a total of 100 boxes. No. of boxes loaded by Night workers = 3/4 x 100 = 75 No. of Night workers = 4/5 x 100 = 80 total no. of boxes loaded by both workers = 175 total no. of boxes loaded by day workers = 100 fraction of boxes loaded by day workers out of the total = 100/175 = 4/7 The closest answer is 4/5 which is D. But the correct answer is 5/8 which is E. You need to make a new thread for a new question, put down the question and your method. Hi, There was a thread already and have posted the question on that thread. [url]helpmewiththeanswerratesratioquestion102404.html[/url] I went thru the answers posted which i understand but i can't see why my reasoning is wrong. Appreciate your response



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Re: Work Problems
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24 Sep 2011, 09:48
gmatyro wrote: Hi, There was a thread already and have posted the question on that thread. [url]helpmewiththeanswerratesratioquestion102404.html[/url] I went thru the answers posted which i understand but i can't see why my reasoning is wrong. Appreciate your response
Have posted the issue in your solution in that thread itself. If you want me to look at a particular question or your solution, just put it down in the corresponding thread and send me a pm. I will look into it.
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Re: Work Problems
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24 Sep 2011, 16:41
Hi,
Is there a way to solve the problem by solving for the portion of X done in the first 14 days and subtract the result from X? I keep getting the wrong answer with the following:
X/5 = R*4T/5 R = X/(4T) 14 days later.. or T/2 X/(4T)*T/2 = X/8 So for the remainder period... XX/8 = 7X/8
would appreciate any help that would pinpoint where this fails.



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Re: Work Problems
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29 Sep 2011, 03:23
syh244 wrote: Hi,
Is there a way to solve the problem by solving for the portion of X done in the first 14 days and subtract the result from X? I keep getting the wrong answer with the following:
X/5 = R*4T/5 R = X/(4T) 14 days later.. or T/2 X/(4T)*T/2 = X/8 So for the remainder period... XX/8 = 7X/8
would appreciate any help that would pinpoint where this fails. Sure you can do it that way too. The error is that the month consists of 30 days (given) so you need to find the work done in 16 days (so that 2 weeks i.e. 14 days are leftover) and subtract that from X. (X/4T) * 16T/30 = 2X/15 X  2X/15 = 13X/15
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Re: A software programmer does 20% of the work in 80% of the
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13 Apr 2012, 04:21
taking into account the assumptions about 20% of work during the 80% of time and vice versa we get
(1) 30 days*80%=24days X work *20%=x/5 (2) 30*20%=6 days X*80%=4x/5 we need to find out the amount of work, done during the last 14 days according to the (2) we already have the amount of work, done in last 6 days  4x/5
rest will be calculated based on the data from (1) knowing that during each stage work was done at constant rate, we can set a proportion (x/5)/24*8=x/15
and now we just sum up two pieces of work x/15+(4x)/5=13x/15



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Re: Work Problem  Need help on this.
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01 Dec 2012, 04:55
manukumar wrote: A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, How many lines of code were written in the last two weeks, in terms of X?
1) 13x/15 2) 7x/15 3) 7x/60 4) 2x/3 5) x/2 Pick nos. Take x = 60 1st stage > 20% of the work in 80% of the time So 20% of 60 = 12 and 80% of 30 (nos of days) = 24 So he writes 12 lines of code in 1st 24 days 2nd stage > 80% of the work in the remaining 20% of the time so he writes 48 lines of code in last 6 days.The 2 boldface are your rates. In the last 14 days comprises of both the stages. in the 1st 8 days he writes at the rate of\(\frac{12}{24} \frac{lines}{days}\) so he writes 4 lines ( \(8 * \frac{12}{24}\)) in the last 6 days he writes at the rate of\(\frac{48}{6}\) lines / days so he writes 48 lines (\(6 *\frac{48}{6}\)) totally he writes 52 lines. This is the final value / target value. Substitute X = 60 and check which one results in 52. Only option A gives 52 when x = 60. Cheers



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Re: A software programmer does 20% of the work in 80% of the
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22 Aug 2014, 07:08
Total work  x lines Total time  30 days
20% work done in 80% time... given 20% of work= x/5 80% of time=30*0.8=24 days Therefore rate for first 24 days=(x/5)/24=x/120
We have been asked to compute work completed in last 2 weeks, i.e. last 14 days Work done in last 14 days=Total workwork done in first 16 days = x[(x/120)*16] = x(2x/15) = 13x/15 Ans= A



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A software programmer does 20% of the work in 80% of the
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25 Aug 2014, 11:56
This question can be answered without any computation. As the 80% of work is done in the last 6 days( 20% of 30 days). Then the work done in the last 14 days must be more than 80% i.e. 4/5 (For the possible answer the numerator must be greater than half of the denimenator) and there are two possible options A (13x/15 ) and D (2x/3 ) Clearly D is just 66.67% and the obvious choice is answer choice A.
Or, if we want to kill some time and do the tedious job of computing, we can do the same as follows : For first part, the time spent is is 80% of 30 days = 30*0.8 =24 days ( Here the programmer does 20% of the work (x) i.e. 1x/5)
For the second part, the time spent is 20% of 30 days= 30*0.2= 6 days ( Here the programmer does 80% of work (x) i.e. 4x/5)
Now lets see, what part of work the programmer does in last 14 days.
Last 14 days= 8 days + 6 days (last 6 days) = [(1x/5)*(1/24)]*8 + 4x/5 =1x/15 +4x/5 =13x/15



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Re: A software programmer does 20% of the work in 80% of the
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03 Sep 2015, 12:51
Here is the pictorial representation of the situation: Work = X Time = 30 days Last 15 days work 1) 20% = 1/5X 80% = 24 days 8 days of work = 24 days of work/3 = 1/3*1/5x = 1/15*x 2) 80% = 4/5X 20% = 6 days 6 days of work = 4/5*x Last 15 days will be 8 days from the 1) and 6 days from 2) = (4/5+1/15)*x = 13/15*x
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Re: A software programmer does 20% of the work in 80% of the time, and 80%
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25 Oct 2016, 00:27
Bunuel wrote: A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, what fraction of the work did he complete in the last two weeks, in terms of X?
A. 13x/15 B. 7x/15 C. 7x/60 D. 2x/3 E. x/2 Total Work = X lines 20% Total Work = (20/100)X = X/5 lines 80% Total Work = (80/100)X = 4X/5 lines 20% Total Time = (20/100)30 = 6 Days 80% Total Time = (80/100)30 = 24 Days Last two weeks = 2*7 = 14 days Amount of work done done in last 6 of these 14 days = 80% Total Work = 4X/5 Lines Amount of work done done in First 8 of these 14 days = (8/24)*(X/5 lines) = X/15 Lines Total Work done in last 14 days = (4X/5) +(X/15) Lines = 13X/15 Lines Answer: option A
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A software programmer does 20% of the work in 80% of the
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16 Nov 2016, 09:36
vivatran wrote: A software programmer does 20% of the work in 80% of the time, and 80% of the work in the remaining 20% of the time. If the code he writes is X lines long and he was given one month (30 days) to accomplish the task, then, assuming that the programmer works at a constant rate in each of the two stages, How many lines of code were written in the last two weeks, in terms of X?
A. 13x /15 B. 15x/15 C. 7x/15 D. 2x/30 E. 13x/30 I had the same approach as VeritasPrepKarishma had. we can easily eliminate B, C, D, and E right away. in the last 6 days, he did 80% of the job. therefore, in last 2 weeks, he finished more than 80% of the work. B = X, or 100%  CLEARLY not C = slightly more than 50%. 9x/15 = 3x/5 = 60%. but this is way more than 7x/15 D = way too small E = way too small now..to verify we know that in first 24 days, he did x/5 work. each day, he did x/120 work. in 8 days, he did 8x/120 work, or 4x/60 or x/15. in last 6 days, he did 4x/5 work. total work done in last 2 weeks: 4x/5 + x/15 multiply first one by 3: 12x/15 + x/15 = 13x/15 answer is A. I believe it should be a sub600 level question, if the answer choices are not changed so that to not eliminate incorrect ones so easy.



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