When Mr Andy is 42 years old, his child is 6 years old. In how many years will he be 5 times as old as his child?
|
Mr Andy |
His child |
Difference |
Before |
42 |
6 |
36 |
Change |
+ ? |
+ ? |
|
After |
5 u |
1 u |
4 u |
The difference in the age between Mr Andy and his child at first and in the end remains the same.
Difference in the age between Mr Andy and his child
= 5 u - 1 u
= 4 u
4 u = 42 - 6
4 u = 36
1 u = 36 ÷ 4 = 9
Number of years' time so Mr Andy will be 5 times as old as his child
= 9 - 6
= 3
Answer(s): 3