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