The average (arithmetic mean) of 11 numbers is 10. When one number is eliminated, the average of the remaining numbers

This topic has expert replies
Legendary Member
Posts: 2276
Joined: Sat Oct 14, 2017 6:10 am
Followed by:3 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

The average (arithmetic mean) of 11 numbers is 10. When one number is eliminated, the average of the remaining numbers is 9.3. What is the eliminated number?

A. 14
B. 15
C. 16
D. 17
E. 18

[spoiler]OA=D[/spoiler]

Source: Manhattan GMAT

Junior | Next Rank: 30 Posts
Posts: 15
Joined: Sat May 30, 2020 10:48 pm
We know that if mean of \(n\) numbers is \(M\) , then sum of the numbers is \(n\ \cdot\ M\)

So, sum of the 11 numbers is \(11\ \cdot\ 10\ =\ 110\)

After removing one number, sum of remaining numbers is \(9.3\ \cdot\ 10\ =\ 93\)

So the removed number is \(110\ -\ 93\ =\ 17\) D