Question

Given: a=b+2c, b=3c. What is the average of numbers a, b and c?

Answer 1

3c

Explanation:

`average = (a + b + c)/(3)`

Substitute a= b +2c:

`(a + b + c)/(3) = (b + 2c + b + c)/(3) \\ (a + b + c)/(3) = (2b + 3c)/(3)`

Substitute b= 3c:

`(a + b + c)/(3) = (2(3c) + 3c)/(3) \\ (a + b + c)/(3) = (6c + 3c)/(3) \\ (a + b + c)/(3) = (9c)/(3) \\ (a + b + c)/( 3) = 3c`

Thus, the average of the 3 numbers is 3c.