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by mgmt_gmat » Fri Feb 12, 2010 2:34 am
A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member
committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4
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by sanju09 » Fri Feb 12, 2010 5:07 am
mgmt_gmat wrote:A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member
committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4
SELECTION or COMBINATION

The question is: 20C5/20C4 =?

20C5/20C4 = {20! / (5! 15!)}/ {20! / (4! 16!)} = (4! 16!)/ (5! 15!) = [spoiler]16/5[/spoiler].

[spoiler]C[/spoiler]
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by komal » Tue Feb 16, 2010 7:40 pm
mgmt_gmat wrote:A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member
committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4
5 members can be chosen out of 20 members in 20C5 ways
4 members can be chosen out of 20 members in 20C4 ways

Ratio is : 20C5/20C4
= 16/5
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by thephoenix » Tue Feb 16, 2010 8:36 pm
its 20C5/20C4=16/5

the no. of selection of 5 members from 20 is 20C5
and that for 4 members is 20C4

ratio is 20C5/20C4=16/5
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by akahuja143 » Tue Feb 16, 2010 8:59 pm
I would go with c
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