Question

what number must be added to 6, 16 and 8 to get an average of 13

Answer 1

22 must be added to 6, 16, and 8 to get an average of 13.

Solution:

We know that,

Average = Total / Number of Elements

Adding 6, 16, and 8 we get 30. Total has to be divisible by 4 as we will add one more number and that must be divisible by 4 giving an average of 13. If we add 22 it can be divided by 4 leaving an average 13(i.e. 62 / 4).

Hence, 22 must be added to 6, 16, and 8 to get an average of 13.

Answer 2

$let \: no \: be \: x \\ \frac{6 + 16 + 8 + x}{4} = 13 \\ 30 + x = 13 \times 4 \\ x = 52 - 30 \\ x = 22$