Club X , Club Y

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Club X , Club Y

by sands_of_time » Tue May 12, 2009 5:14 am
Is the number of members of club X greater than the number of members of club Y ?

a) Of the members of club X, 20 percent are also members of club Y.

b) Of the members of club Y, 30 percent are also members of club X.

OA C

This is a question from OG. Can somebody kindly provide a clear explanation ? ( as the OG doesn't :roll: )
Source: — Data Sufficiency |

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by bluementor » Tue May 12, 2009 6:23 am
No. of members in club X = x
No. of members in club Y = y

is x>y?

Statement 1: 0.2x members in club X are also in club Y

we have no info on y. insufficient.

Statement 2: 0.3y members in club Y are also in club X

we have no info on x, insufficient.

Both statements together:

0.2x members in club X who are also in club Y = 0.3y members in club members who also in club X

*basically we are talking about the same group of people in both sides of the equation, i.e. those with dual membership.

so,

0.2x = 0.3y
x/y = 1.5

since x and y must both be positive, we can definitely conclude that x>y. Sufficient.

Choose C.

-BM-