Question

A boy is now $a$ years old, and his father is $5a$ years old. What will the father be when the boy is $3a$ years old? How old was the father when the boy was born?

• A. $7a,4a$ years
• B. $4a,10a$ years
• C. $12a,3a$ years
• D. $15a,3a$ years

Answer 1

The correct option is A $7a,4a$ years

When the boy is $a$ years old, the father is $5a$ years old
So, when the boy is $3a$ years old, its age increased by $2a$. This means, fathers age also increased by $2a$ years and will be $5a+2a=7a$ years old.
And when the boy was born, fathers age will be $5a-a=4a$ years old.