When Mr Cole is 19 years old, his son is 5 years old. In how many years will he be 3 times as old as his son?
|
Mr Cole |
His son |
Difference |
Before |
19 |
5 |
14 |
Change |
+ ? |
+ ? |
|
After |
3 u |
1 u |
2 u |
The difference in the age between Mr Cole and his son at first and in the end remains the same.
Difference in the age between Mr Cole and his son
= 3 u - 1 u
= 2 u
2 u = 19 - 5
2 u = 14
1 u = 14 ÷ 2 = 7
Number of years' time so Mr Cole will be 3 times as old as his son
= 7 - 5
= 2
Answer(s): 2