Billy's age is
37 of his granduncle's. His granduncle will be 71 years old in 8 years' time. In how many years' time will Billy's age be
35 that of his granduncle's?
| |
Billy |
His granduncle |
Difference |
| Before |
3x1 =
3 u |
7x1 =
7 u |
4x1 =
4 u |
| Change 1 |
+ 8 |
+ 8 |
|
| After |
|
71 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
3x2 =
6 u |
5x2 =
10 u |
2x2 =
4 u |
The age difference between Billy and his granduncle remains unchanged.
LCM of 4 and 2 is 4.
7 u + 8 = 71
7 u = 71 - 8
7 u = 63
1 u = 63 ÷ 7 = 9
Number of years' time when Billy's age will be
35 that of his granduncle's age
= 6 u - 3 u
= 3 u
= 3 x 9
= 27
Answer(s): 27
