Problem Solving

thedude232 wrote:If wx=y, what is the value of xy?

(1) w(x^2) = 16

(2) y = 4

Thanks!

Given : wx = y

Question : xy = ?

Statement 1) w(x^2) = 16
i.e. (wx) * x = 16
i.e. y * x = 16
SUFFICIENT

Statement 2) y=4
Doesn't give us any clue about x therefore INSUFFICIENT

Answer: Option A

If wx = y, what is the value of xy?

1. w(x^2) = 16
2. y = 4

Question Stem:
xy = y^2/w

St 1
w=16/x^2
So, xy = (y^2) *(x^2/16) =>xy = 16 Sufficient
St 2
y=4 Not sufficient
IMO:A

There are two ways to solve this question, either

wx = y
multiplying x on both sides - x can be +ive or -ive will not matter since we are dealing with equality symbol.

wx * x = x * y = 16
xy = 16

answer A.

other way is to substitute values for w & x for wx^2 = 16 & get value for xy which come 16 always.

answer A.

Forget conventional ways of solving math questions. In PS, IVY approach is the easiest and quickest way to find the answer.


If wx=y, what is the value of xy?

(1) w(x^2) = 16

(2) y = 4
transforming the original condition, wx=y--> since the question asks for xy, xy=x(wx)=wx^2=?. Therefore the answer is A.


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