Tommy's age is
25 of his grandaunt's. His grandaunt will be 58 years old in 18 years' time. In how many years' time will Tommy's age be
23 that of his grandaunt's?
| |
Tommy |
His grandaunt |
Difference |
| Before |
2x1 =
2 u |
5x1 =
5 u |
3x1 =
3 u |
| Change 1 |
+ 18 |
+ 18 |
|
| After |
|
58 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
2x3 =
6 u |
3x3 =
9 u |
1x3 =
3 u |
The age difference between Tommy and his grandaunt remains unchanged.
LCM of 3 and 1 is 3.
5 u + 18 = 58
5 u = 58 - 18
5 u = 40
1 u = 40 ÷ 5 = 8
Number of years' time when Tommy's age will be
23 that of his grandaunt's age
= 6 u - 2 u
= 4 u
= 4 x 8
= 32
Answer(s): 32
