Caden's age is
17 of his granduncle's. His granduncle will be 71 years old in 15 years' time. In how many years' time will Caden's age be
12 that of his granduncle's?
| |
Caden |
His granduncle |
Difference |
| Before |
1x1 =
1 u |
7x1 =
7 u |
6x1 =
6 u |
| Change 1 |
+ 15 |
+ 15 |
|
| After |
|
71 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x6 =
6 u |
2x6 =
12 u |
1x6 =
6 u |
The age difference between Caden and his granduncle remains unchanged.
LCM of 6 and 1 is 6.
7 u + 15 = 71
7 u = 71 - 15
7 u = 56
1 u = 56 ÷ 7 = 8
Number of years' time when Caden's age will be
12 that of his granduncle's age
= 6 u - 1 u
= 5 u
= 5 x 8
= 40
Answer(s): 40
