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# If 20 percent of the members in club A are members of club B also,

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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
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gamjatang wrote:
If 20 percent of the members in club A are members of club B also, which club has more members?

1). 30 percent of the members of B are members of A also.
2). A has 600 members.

X = number of members in club A
Y = number of members in club B

1)

0.2X = 0.3Y
X = 3/2Y
X > Y
Sufficient

2)
X = 600
Insufficient

Thus, (A).

and um...what if club A has 1000 members and B has 100?

A = 1000 and B = 100 would contradict info given in the stem. We are told that 20% of the members in club A are members of club B also, if there are 100 people in A, then it means that 200 of them are members of B too. Thus B cannot have less than 200 members.

From the stem we have that {Both} = 0.2A. (1) says that {Both}= 0.3B, hence 0.2A = 0.3B --> A/B = 3/2 --> A > B.

Hope it's clear.
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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
0.2X = 0.3Y is wrong, because it is not same , as it is not given those 20 % and 30 percent are common to both...
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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
anand.prakash90@gmail.com wrote:
0.2X = 0.3Y is wrong, because it is not same , as it is not given those 20 % and 30 percent are common to both...

No, that's not correct.

20 percent of the members in club A are members of club B also, means that {Both} = 0.2A.
30 percent of the members of B are members of A also, means that {Both}= 0.3B.

Therefore, 0.2A = 0.3B --> A/B = 3/2 --> A > B.

Check question about the same concept: is-the-number-of-members-of-club-x-greater-than-the-number-128641.html
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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
1)0.2a = 0.3b
a = 3/2b
a > b
Sufficient

2)
a = 600
b = ?
insufficient
A it is
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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
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Re: If 20 percent of the members in club A are members of club B also, [#permalink]
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