Question

To obtain an average (arithmetic mean) of exactly 2/3, what fraction must be added to 1/6, 1/2, and 1/3?

A. 2/3
B. 1/1
C. 3/2
D. 5/3

Answer 1

D. 5/3

Explanation:

`(1/6+1/2+1/3+x)/(4) =2/3`

`1/6+1/2+1/3+x=8/3`

`x=8/3-1/6-1/2-1/3`

`x=8/3-1/6-3/6-2/6`

`x=8/3-6/6`

`x=16/6-6/6=10/6`

simplified

`x=5/3`

Hope this helps