Archie is 2 years old. His mother is 38 years older than him. In how many years will Archie's mother be 3 times as old as Archie?
| |
His mother |
Archie |
Difference |
| Before |
40 |
2 |
38 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Archie and his mother at first and in the end remains the same.
Difference in the age between Archie and his mother
= 3 u - 1 u
= 2 u
2 u = 38
1 u = 38 ÷ 2 = 19
The increase in age of Archie and his mother remains the same.
Number of years' time so Archie's mother will be 3 times as old as Archie
= 19 - 2
= 17
Answer(s): 17
