Brandon's age is
14 of his granduncle's. His granduncle will be 61 years old in 5 years' time. In how many years' time will Brandon's age be
12 that of his granduncle's?
| |
Brandon |
His granduncle |
Difference |
| Before |
1x1 =
1 u |
4x1 =
4 u |
3x1 =
3 u |
| Change 1 |
+ 5 |
+ 5 |
|
| After |
|
61 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x3 =
3 u |
2x3 =
6 u |
1x3 =
3 u |
The age difference between Brandon and his granduncle remains unchanged.
LCM of 3 and 1 is 3.
4 u + 5 = 61
4 u = 61 - 5
4 u = 56
1 u = 56 ÷ 4 = 14
Number of years' time when Brandon's age will be
12 that of his granduncle's age
= 3 u - 1 u
= 2 u
= 2 x 14
= 28
Answer(s): 28
