Question

Question 11

The mean of five numbers is 16.
When two extra numbers are included the mean of the seven numbers is 20.
Find the mean of the two extra numbers.

Answer 1

30

Explanation:

The mean of 5 numbers is 16 => the sum is 16 x 5 = 80

The mean of 7 numbers is 20 => the sum is 20 x 7 = 140

So, the sum of the 2 extra numbers is 140 - 80 = 60
And the mean will be 60 : 2 = 30

Hope it helps :D