When Mr Ben is 30 years old, his child is 4 years old. In how many years will he be 3 times as old as his child?
| |
Mr Ben |
His child |
Difference |
| Before |
30 |
4 |
26 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Mr Ben and his child at first and in the end remains the same.
Difference in the age between Mr Ben and his child
= 3 u - 1 u
= 2 u
2 u = 30 - 4
2 u = 26
1 u = 26 ÷ 2 = 13
Number of years' time so Mr Ben will be 3 times as old as his child
= 13 - 4
= 9
Answer(s): 9
