Mr. Jones is the Chairman of a committee. In how many ways

This topic has expert replies
Moderator
Posts: 2205
Joined: Sun Oct 15, 2017 1:50 pm
Followed by:6 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Source: EMPOWERgmat

Mr. Jones is the Chairman of a committee. In how many ways can a committee of 5 be chosen from 10 people given that Mr. Jones must be one of them?

A. 126
B. 252
C. 459
D. 3024

The OA is A.

Junior | Next Rank: 30 Posts
Posts: 10
Joined: Wed Oct 03, 2018 10:34 am

by Ash Mo » Sat Oct 13, 2018 11:32 am
In this question some doubt does arise as to whether Mr.Jones is a part of the 10. Assuming he isn't the answer would be 10C4, which is not among the options.

Assuming that Mr.Jones is a member of the 10 and knowing that he must be selected, we have 9 other people who can be selected for 4 spots on the committee.
This gives us the answer as 9C4, which is 126

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7223
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Sat Oct 13, 2018 5:32 pm
BTGmoderatorLU wrote:Source: EMPOWERgmat

Mr. Jones is the Chairman of a committee. In how many ways can a committee of 5 be chosen from 10 people given that Mr. Jones must be one of them?

A. 126
B. 252
C. 459
D. 3024
Since Mr. Jones must be one of the chosen people, we have to choose 4 from the remaining 9 people for the committee, and the number of ways to do that is:

9C4 = (9 x 8 x 7 x 6)/(4 x 3 x 2) = 3 x 7 x 6 = 126

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage