|
Author |
Message |
|
TAGS:
|
|
|
Senior Manager
Joined: 11 Jan 2006
Posts: 277
Location: Chennai,India
Followers: 1
Kudos [?]:
3
[0], given: 0
|
can someone pls solve n explain these problems?
Attachments
 math1.doc [232.5 KiB]
Downloaded 59 times
_________________
vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma
|
|
|
|
|
|
|
Manager
Joined: 15 Aug 2005
Posts: 202
Location: New York
Followers: 1
Kudos [?]:
1
[0], given: 0
|
The area is 18
AD = 10
AE =5
CD=4
CE=3
|
|
|
|
|
|
Director
Joined: 17 Dec 2005
Posts: 559
Location: Germany
Followers: 1
Kudos [?]:
1
[0], given: 0
|
Before calculate you should establish why those triangles are equal.
In Ds it may hurt you doing otherwise.
|
|
|
|
|
|
Senior Manager
Joined: 11 Jan 2006
Posts: 277
Location: Chennai,India
Followers: 1
Kudos [?]:
3
[0], given: 0
|
wait! first lemme get it straight, what is the area of that quad? l*b right
celix if u tellin area = 18 ==> AB*BC =6*3 , but since as per ur solution if cd=4 then cb =4 and then area will be 6*4 ...
where am i going wrong, please explain
_________________
vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma
|
|
|
|
|
|
VP
Joined: 21 Sep 2003
Posts: 1079
Location: USA
Followers: 2
Kudos [?]:
17
[0], given: 0
|
1. 18
Triangle ABD and triangle ECD are similar triangles (share the same angle)
Hence EC = 3 (3,4,5 triangle)
Also triangle AEF and ECD are similar triangles, since they are formed by parallel lines cut by a line (transversal as math geeks would call it)
Infact these traingles are equal since AE = ED = 5
Area of the quadrilateral = 1/2 (4) (3+6) = 18
2. C (It will not pass), assuming that each of the L's vote YES on the bill, Otherwise it is E.
From #1 we get total L's who vote = (55/100)*400*(85/100) = 187 (But we don't know about Rs and Ds.
From #2 we know that none of the Rs or Ds vote.
Hence total votes = 187 < 189. Hence C. (or E if we don't know each one will vote YES or NO)
3. 11 (div by 78) + 9 (div by 91) = 20.
78*10 = 780 (including 78 there are 10 numbers. Excluding 78 there are 9 of them)
78+78*2 = 936 < 1000. So 2 more available.
Hence No divisible by 78 =9+2 = 11
Similarly for 91 there are 10-1 = 9
Total = 20.
OA's please?
_________________
"To dream anything that you want to dream, that is the beauty of the human mind. To do anything that you want to do, that is the strength of the human will. To trust yourself, to test your limits, that is the courage to succeed."
- Bernard Edmonds
|
|
|
|
|
|
Director
Joined: 17 Dec 2005
Posts: 559
Location: Germany
Followers: 1
Kudos [?]:
1
[0], given: 0
|
Approximation is very fast for the third question
xxx is a multiple of either 78 or 91
You see 10*78 + 2*78 = 936
So there are 11 multiples of 78
Similiary for 91:
10*91=91
So there are 9 multples of 91
Next step are there multiples counted twice?
91= 7*13
78= 2*3*13
Both are equal if 2*3 and 7 have a common multiple, wich is 7 and 6 respectively. Notice that above you needn't to look out for common multiples above 999.
So 7*2*3*13=546, or 6*7*13 is counted twice
So 19 is the answer
|
|
|
|
|
|
Senior Manager
Joined: 11 Jan 2006
Posts: 277
Location: Chennai,India
Followers: 1
Kudos [?]:
3
[0], given: 0
|
giddi77 wrote: 1. 18
Triangle ABD and triangle ECD are similar triangles (share the same angle)
Hence EC = 3 (3,4,5 triangle)
Also triangle AEF and ECD are similar triangles, since they are formed by parallel lines cut by a line (transversal as math geeks would call it)
Infact these traingles are equal since AE = ED = 5
Area of the quadrilateral = 1/2 (4) (3+6) = 18
2. C (It will not pass), assuming that each of the L's vote YES on the bill, Otherwise it is E.
From #1 we get total L's who vote = (55/100)*400*(85/100) = 187 (But we don't know about Rs and Ds.
From #2 we know that none of the Rs or Ds vote.
Hence total votes = 187 < 189. Hence C. (or E if we don't know each one will vote YES or NO)
3. 11 (div by 78) + 9 (div by 91) = 20.
78*10 = 780 (including 78 there are 10 numbers. Excluding 78 there are 9 of them)
78+78*2 = 936 < 1000. So 2 more available.
Hence No divisible by 78 =9+2 = 11
Similarly for 91 there are 10-1 = 9
Total = 20.
OA's please?
 u nailed them all , can u please explain the 3rd
how did u come to this conclusion ( i know its very silly) i am not able to understand it.
_________________
vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma
|
|
|
|
|
|
Director
Joined: 17 Dec 2005
Posts: 559
Location: Germany
Followers: 1
Kudos [?]:
1
[0], given: 0
|
Are you sure it's 20?
|
|
|
|
|
|
VP
Joined: 21 Sep 2003
Posts: 1079
Location: USA
Followers: 2
Kudos [?]:
17
[0], given: 0
|
allabout wrote:
Next step are there multiples counted twice?
91= 7*13
78= 2*3*13
Both are equal if 2*3 and 7 have a common multiple, wich is 7 and 6 respectively. Notice that above you needn't to look out for common multiples above 999.
So 7*2*3*13=546, or 6*7*13 is counted twice
So 19 is the answer
Tooo good allabout! Thanks for explaining it very clearly! I'll remember this.
_________________
"To dream anything that you want to dream, that is the beauty of the human mind. To do anything that you want to do, that is the strength of the human will. To trust yourself, to test your limits, that is the courage to succeed."
- Bernard Edmonds
|
|
|
|
|
|
Manager
Joined: 15 Aug 2005
Posts: 202
Location: New York
Followers: 1
Kudos [?]:
1
[0], given: 0
|
razrulz wrote: wait! first lemme get it straight, what is the area of that quad? l*b right
celix if u tellin area = 18 ==> AB*BC =6*3 , but since as per ur solution if cd=4 then cb =4 and then area will be 6*4 ...
where am i going wrong, please explain
The area = (AB+CE)*BC/2
|
|
|
|
|
|
Senior Manager
Joined: 11 Jan 2006
Posts: 277
Location: Chennai,India
Followers: 1
Kudos [?]:
3
[0], given: 0
|
hey all about, i got this question from a grp! someone had posted the questions and answers and asked for explanations. by far , her answer for the 3rd question was 20 , so i am not sure !
so i dont have a OA. I am sorry!
_________________
vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma
|
|
|
|
|
|
Director
Joined: 17 Dec 2005
Posts: 559
Location: Germany
Followers: 1
Kudos [?]:
1
[0], given: 0
|
razrulz wrote: hey all about, i got this question from a grp! someone had posted the questions and answers and asked for explanations. by far , her answer for the 3rd question was 20 , so i am not sure !
so i dont have a OA. I am sorry!
Ok, the question may be ambiguous, since "different numbers" is omitted.
Generally 546 is one number, so the answer is 19 not 20.
|
|
|
|
|
|
Senior Manager
Joined: 11 Jan 2006
Posts: 277
Location: Chennai,India
Followers: 1
Kudos [?]:
3
[0], given: 0
|
allabout wrote: razrulz wrote: hey all about, i got this question from a grp! someone had posted the questions and answers and asked for explanations. by far , her answer for the 3rd question was 20 , so i am not sure !
so i dont have a OA. I am sorry! Ok, the question may be ambiguous, since "different numbers" is omitted. Generally 546 is one number, so the answer is 19 not 20. AYE AYE SIR !  thnks again
_________________
vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma
|
|
|
|
|
|
SVP
Joined: 16 Oct 2003
Posts: 1957
Followers: 2
Kudos [?]:
14
[0], given: 0
|
According to me the two possible answers are 18 and 22.5. Since 18 is the only one given it should be it.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
close
