When Mr Perry is 41 years old, his child is 2 years old. In how many years will he be 4 times as old as his child?
|
Mr Perry |
His child |
Difference |
Before |
41 |
2 |
39 |
Change |
+ ? |
+ ? |
|
After |
4 u |
1 u |
3 u |
The difference in the age between Mr Perry and his child at first and in the end remains the same.
Difference in the age between Mr Perry and his child
= 4 u - 1 u
= 3 u
3 u = 41 - 2
3 u = 39
1 u = 39 ÷ 3 = 13
Number of years' time so Mr Perry will be 4 times as old as his child
= 13 - 2
= 11
Answer(s): 11