When Mr Sam is 33 years old, his child is 3 years old. In how many years will he be 4 times as old as his child?
| |
Mr Sam |
His child |
Difference |
| Before |
33 |
3 |
30 |
| Change |
+ ? |
+ ? |
|
| After |
4 u |
1 u |
3 u |
The difference in the age between Mr Sam and his child at first and in the end remains the same.
Difference in the age between Mr Sam and his child
= 4 u - 1 u
= 3 u
3 u = 33 - 3
3 u = 30
1 u = 30 ÷ 3 = 10
Number of years' time so Mr Sam will be 4 times as old as his child
= 10 - 3
= 7
Answer(s): 7
