Mark is 5 years old. His uncle is 40 years older than him. In how many years will Mark's uncle be 6 times as old as Mark?
| |
His uncle |
Mark |
Difference |
| Before |
45 |
5 |
40 |
| Change |
+ ? |
+ ? |
|
| After |
6 u |
1 u |
5 u |
The difference in the age between Mark and his uncle at first and in the end remains the same.
Difference in the age between Mark and his uncle
= 6 u - 1 u
= 5 u
5 u = 40
1 u = 40 ÷ 5 = 8
The increase in age of Mark and his uncle remains the same.
Number of years' time so Mark's uncle will be 6 times as old as Mark
= 8 - 5
= 3
Answer(s): 3
