Tommy is 2 years old. His mother is 22 years older than him. In how many years will Tommy's mother be 3 times as old as Tommy?
| |
His mother |
Tommy |
Difference |
| Before |
24 |
2 |
22 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Tommy and his mother at first and in the end remains the same.
Difference in the age between Tommy and his mother
= 3 u - 1 u
= 2 u
2 u = 22
1 u = 22 ÷ 2 = 11
The increase in age of Tommy and his mother remains the same.
Number of years' time so Tommy's mother will be 3 times as old as Tommy
= 11 - 2
= 9
Answer(s): 9
