The average of 16 and x is 21. Find x.

The average of 16 and x is 21. Find x.

The average of 2 numbers is the sum of the 2 numbers divided by 2. So we have:
(16 + x)/2 = 21

Cross multiply:
16 + x = 21*2
16 + x = 42

To solve this equation, we type this expression into the search engine and get x = 26.

Check our work by restating our answer:
The average of 16 and 26 is 21. TRUE.