Vincent's age is
16 of his grandaunt's. His grandaunt will be 63 years old in 9 years' time. In how many years' time will Vincent's age be
12 that of his grandaunt's?
| |
Vincent |
His grandaunt |
Difference |
| Before |
1x1 =
1 u |
6x1 =
6 u |
5x1 =
5 u |
| Change 1 |
+ 9 |
+ 9 |
|
| After |
|
63 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x5 =
5 u |
2x5 =
10 u |
1x5 =
5 u |
The age difference between Vincent and his grandaunt remains unchanged.
LCM of 5 and 1 is 5.
6 u + 9 = 63
6 u = 63 - 9
6 u = 54
1 u = 54 ÷ 6 = 9
Number of years' time when Vincent's age will be
12 that of his grandaunt's age
= 5 u - 1 u
= 4 u
= 4 x 9
= 36
Answer(s): 36
