Carl is 5 years old. His uncle is 36 years older than him. In how many years will Carl's uncle be 4 times as old as Carl?
| |
His uncle |
Carl |
Difference |
| Before |
41 |
5 |
36 |
| Change |
+ ? |
+ ? |
|
| After |
4 u |
1 u |
3 u |
The difference in the age between Carl and his uncle at first and in the end remains the same.
Difference in the age between Carl and his uncle
= 4 u - 1 u
= 3 u
3 u = 36
1 u = 36 ÷ 3 = 12
The increase in age of Carl and his uncle remains the same.
Number of years' time so Carl's uncle will be 4 times as old as Carl
= 12 - 5
= 7
Answer(s): 7
