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Source: — Data Sufficiency |
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by ssmiles08 » Sun May 31, 2009 11:55 am
I have to say C on this one.

Choice 1 gives the ratio before, but not after: Insuff

Choice 2 gives the ratio after, but not before: Insuff

together:

(7x-3)/4x = 3/2

14x - 6 = 12x

x = 3

nickels remaining is 2x = 6 remaining nickels
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by mikeCoolBoy » Sun May 31, 2009 12:06 pm
IMO C

statement 1 says that the original ratio was 7:4

then the jar could have contained 7 pennies and 4 nickels or 14 pennies and 8 nickels or any other combinations.
insufficient.

statement 2 says that the new ratio is 3:2
this means that the new jar can contains 3 pennies and 2 nickels or 6 pennies and 4 nickels or any other combinations.

The combinations for the original jar could have been
6 pennies and 2 nickels
9 pennies and 4 nickels
....
insufficient

both statements together.

We now that the number of nickels is the same and that the total number is 3 less than the previous one.

N = number of nickels

Initially the jar contained 7/4N + N
after removing 3 pennies the jar contains 3/2N + N

therefore 7/4N + N -3 = 3/2N + N ---> N= 12
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by ssmiles08 » Sun May 31, 2009 2:06 pm
ssmiles08 wrote:I have to say C on this one.



nickels remaining is 2x = 6 remaining nickels
Sorry my mistake:

x = 3

12 nickels remain: 4x = 4(3) = 12
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by aj5105 » Mon Jun 01, 2009 4:20 am
Statement (1)

P/N = 7x/4x

Insufficient


Statement (2)

(P - 3)/N = 3x/2x

Insufficient


(1) + (2)

Substitute for P,we get N = 12

Sufficient

(C)
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Answer : C

by brick2009 » Mon Jun 01, 2009 9:49 pm
1.) P/N = 7/4 (insufficient)

2.) (p-3)/N = 3/2 (again insufficient on its own)

simplifying: p/N -3/N = 3/2
7/4 -3/N = 3/2

N = 12, P = 21

C
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