When Mr Harry is 36 years old, his son is 6 years old. In how many years will he be 3 times as old as his son?
| |
Mr Harry |
His son |
Difference |
| Before |
36 |
6 |
30 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Mr Harry and his son at first and in the end remains the same.
Difference in the age between Mr Harry and his son
= 3 u - 1 u
= 2 u
2 u = 36 - 6
2 u = 30
1 u = 30 ÷ 2 = 15
Number of years' time so Mr Harry will be 3 times as old as his son
= 15 - 6
= 9
Answer(s): 9
