The average age of three boys is 20 years and their ages are in proportion 3:5:7.

The average age of three boys is 20 years and their ages are in proportion 3:5:7. What is the age in years of the eldest boy?

Quiz

Answer/Solution

28

Steps/Work

3x + 5x + 7x = 60
x =4
7x = 28
Answer:C