If the mean of 3 ages is 15 and the ages of two persons are 10 and 20, what is the age of the third person?
If the mean of 3 ages is 15 and the ages of two persons are 10 and 20, what is the age of the third person?
Explanation
Mean = Total sum ÷ 3 → Total = 15 × 3 = 45
Given ages = 10 and 20 → Sum = 30
Third age = 45 − 30 = 15