Question

If 2a+b=7 and b+2c=23, what is the average of a, b, and c?
a)5 b)7.5 c)15 d)12.25

Answer 1

Option A, 5

Explanation:

If 2a + b = 7 and b + 2c = 23

Then we have to find the average of a, b and c.

In other words we have to find the value of
`(a+b+c)/(3)`

By adding both the equations

(2a + b) + (b + 2c) = 7 + 23

2a + 2b + 2c = 30

2(a + b + c) = 30

(a + b + c) =
`(30)/(2)` = 15

⇒
`((a+b+c))/(3)=(15)/(3)=5`

Therefore, average of a, b and c is 5

Option A, 5 is the answer.