Zeph is 7 years old now. His brother is 21 years older than him. How old will Zeph be when his age is
58 of his brother's age?
| |
Zeph |
His brother |
Difference |
| Before |
|
|
21 |
| Change |
+ ? |
+ ? |
|
| After |
5 u |
8 u |
3 u |
The difference in the age between Zeph and his brother at first and in the end remains unchanged.
Number of years that his brother is older than Zeph
= 8 u - 5 u
= 3 u
3 u = 21
1 u = 21 ÷ 3 = 7
Zeph's age when his age is
58 of his brother's age
= 5 u
= 5 x 7
= 35
Answer(s): 35
