Simon's age is
15 of his grandfather's. His grandfather will be 59 years old in 14 years' time. In how many years' time will Simon's age be
12 that of his grandfather's?
| |
Simon |
His grandfather |
Difference |
| Before |
1x1 =
1 u |
5x1 =
5 u |
4x1 =
4 u |
| Change 1 |
+ 14 |
+ 14 |
|
| After |
|
59 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x4 =
4 u |
2x4 =
8 u |
1x4 =
4 u |
The age difference between Simon and his grandfather remains unchanged.
LCM of 4 and 1 is 4.
5 u + 14 = 59
5 u = 59 - 14
5 u = 45
1 u = 45 ÷ 5 = 9
Number of years' time when Simon's age will be
12 that of his grandfather's age
= 4 u - 1 u
= 3 u
= 3 x 9
= 27
Answer(s): 27
