When Mr Billy is 41 years old, his nephew is 5 years old. In how many years will he be 3 times as old as his nephew?
|
Mr Billy |
His nephew |
Difference |
Before |
41 |
5 |
36 |
Change |
+ ? |
+ ? |
|
After |
3 u |
1 u |
2 u |
The difference in the age between Mr Billy and his nephew at first and in the end remains the same.
Difference in the age between Mr Billy and his nephew
= 3 u - 1 u
= 2 u
2 u = 41 - 5
2 u = 36
1 u = 36 ÷ 2 = 18
Number of years' time so Mr Billy will be 3 times as old as his nephew
= 18 - 5
= 13
Answer(s): 13