Question

A father and his son are $50$ years and $20$ years old respectively$.$ Find the ratio of father's age to his son's age when the son will be $40$ years old$.$

Answer 1

Step $1:$ To find the ratio of father's age to his son's age when the son will be $40$ years old.

Given present age of father $=50$ years

present age of son $=20$ years

Step $2:$ Find the age of father when the son will be $40$ years old

A fter $20$ years the father's age will be $=70$ years

After $20$ years the son's age will be $=40$ years

Step $3:$Now find the ratio of father's age to his son's age

Required Ratio $=70:40$

Step $4:$ Convert ratio into fraction and write its simplest form

$=\frac{70}{40}$

$=\frac{7}{4}$

Hence, the ratio of father's age to his son's age when son will be $40$ years old is $7:4$