Charlie is 7 years old now. His cousin is 21 years older than him. How old will Charlie be when his age is
47 of his cousin's age?
| |
Charlie |
His cousin |
Difference |
| Before |
|
|
21 |
| Change |
+ ? |
+ ? |
|
| After |
4 u |
7 u |
3 u |
The difference in the age between Charlie and his cousin at first and in the end remains unchanged.
Number of years that his cousin is older than Charlie
= 7 u - 4 u
= 3 u
3 u = 21
1 u = 21 ÷ 3 = 7
Charlie's age when his age is
47 of his cousin's age
= 4 u
= 4 x 7
= 28
Answer(s): 28
