What is the number of different committees of 4 people that can be selected from a group of 10 people?

[BTGmoderatorDC]

What is the number of different committees of 4 people that can be selected from a group of 10 people?

A. 20

B. 40

C. 80

D. 120

E. 210



OA E

Source: GMAT Prep

[swerve]

What is the number of different committees of 4 people that can be selected from a group of 10 people?

A. 20

B. 40

C. 80

D. 120

E. 210



OA E

Source: GMAT Prep

We are to determine the number of 4 member committees that can be formed from 10 people. This is simple combination problem since order is not important here.

So, Number of ways = 10C4 = 210.

Therefore, the correct answer is __E__

[Brent@GMATPrepNow]

What is the number of different committees of 4 people that can be selected from a group of 10 people?

A. 20

B. 40

C. 80

D. 120

E. 210



OA E

Source: GMAT Prep

Since the order in which we select the committee members does not matter, we can use combinations to solve this question

We can select 4 people from 10 people in 10C4 ways
10C4 = (10)(9)(8)(7)/(4)(3)(2)(1)
= (10)(9)(7)/(3)(1)
= (10)(3)(7)
= 210

Answer: E

ASIDE: Here's a video on how to reduce your calculations when evaluating combinations like 10C4: https://www.gmatprepnow.com/module/gmat ... /video/789

[Scott@TargetTestPrep]

What is the number of different committees of 4 people that can be selected from a group of 10 people?

A. 20

B. 40

C. 80

D. 120

E. 210



OA E

Source: GMAT Prep

The number of committees that can be selected is:

10C4 = 10! / (4! x 6!) = (10 x 9 x 8 x 7) / (4 x 3 x 2) = 5 x 3 x 2 x 7 = 210.

Answer: E