Liam's age is
27 of his grandmother's. His grandmother will be 59 years old in 3 years' time. In how many years' time will Liam's age be
12 that of his grandmother's?
| |
Liam |
His grandmother |
Difference |
| Before |
2x1 =
2 u |
7x1 =
7 u |
5x1 =
5 u |
| Change 1 |
+ 3 |
+ 3 |
|
| After |
|
59 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x5 =
5 u |
2x5 =
10 u |
1x5 =
5 u |
The age difference between Liam and his grandmother remains unchanged.
LCM of 5 and 1 is 5.
7 u + 3 = 59
7 u = 59 - 3
7 u = 56
1 u = 56 ÷ 7 = 8
Number of years' time when Liam's age will be
12 that of his grandmother's age
= 5 u - 2 u
= 3 u
= 3 x 8
= 24
Answer(s): 24
