Japheth's age is
27 of his granduncle's. His granduncle will be 61 years old in 5 years' time. In how many years' time will Japheth's age be
12 that of his granduncle's?
| |
Japheth |
His granduncle |
Difference |
| Before |
2x1 =
2 u |
7x1 =
7 u |
5x1 =
5 u |
| Change 1 |
+ 5 |
+ 5 |
|
| After |
|
61 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
1x5 =
5 u |
2x5 =
10 u |
1x5 =
5 u |
The age difference between Japheth and his granduncle remains unchanged.
LCM of 5 and 1 is 5.
7 u + 5 = 61
7 u = 61 - 5
7 u = 56
1 u = 56 ÷ 7 = 8
Number of years' time when Japheth's age will be
12 that of his granduncle's age
= 5 u - 2 u
= 3 u
= 3 x 8
= 24
Answer(s): 24
