Justin is 4 years old now. His brother is 20 years older than him. How old will Justin be when his age is
35 of his brother's age?
| |
Justin |
His brother |
Difference |
| Before |
|
|
20 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
5 u |
2 u |
The difference in the age between Justin and his brother at first and in the end remains unchanged.
Number of years that his brother is older than Justin
= 5 u - 3 u
= 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Justin's age when his age is
35 of his brother's age
= 3 u
= 3 x 10
= 30
Answer(s): 30
