To find one fifth of the sum of 10 and a number q, you need to first calculate the sum of 10 and q, and then divide that sum by 5.
The sum of 10 and q is: 10 + q.
Now, divide this sum by 5: (10 + q) / 5.
Therefore, one fifth of the sum of 10 and a number q is (10 + q) / 5.