When Mr Paul is 35 years old, his son is 5 years old. In how many years will he be 4 times as old as his son?
|
Mr Paul |
His son |
Difference |
Before |
35 |
5 |
30 |
Change |
+ ? |
+ ? |
|
After |
4 u |
1 u |
3 u |
The difference in the age between Mr Paul and his son at first and in the end remains the same.
Difference in the age between Mr Paul and his son
= 4 u - 1 u
= 3 u
3 u = 35 - 5
3 u = 30
1 u = 30 ÷ 3 = 10
Number of years' time so Mr Paul will be 4 times as old as his son
= 10 - 5
= 5
Answer(s): 5