Jack is 5 years old. His mother is 30 years older than him. In how many years will Jack's mother be 4 times as old as Jack?
| |
His mother |
Jack |
Difference |
| Before |
35 |
5 |
30 |
| Change |
+ ? |
+ ? |
|
| After |
4 u |
1 u |
3 u |
The difference in the age between Jack and his mother at first and in the end remains the same.
Difference in the age between Jack and his mother
= 4 u - 1 u
= 3 u
3 u = 30
1 u = 30 ÷ 3 = 10
The increase in age of Jack and his mother remains the same.
Number of years' time so Jack's mother will be 4 times as old as Jack
= 10 - 5
= 5
Answer(s): 5
