Question

If the average of 5 numbers is 18, what is their total sum?

• A. 72
• B. 85
• C. 90
• D. 95

Hint:

Multiplication is the fastest route to finding the total sum when the average and count are known. $18 \times 5 = (20-2) \times 5 = 100 - 10 = 90$.

Answer 1

The Correct Option is C

The formula relating average, sum, and count is: $\text{Sum} = \text{Average} \times \text{Count}$.
Given: $\text{Average} = 18$.
Given: $\text{Count} = 5$.
Total Sum $= 18 \times 5$.
Total Sum $= 90$.