Riordan's age is
14 of his grandaunt's. His grandaunt will be 49 years old in 9 years' time. In how many years' time will Riordan's age be
710 that of his grandaunt's?
| |
Riordan |
His grandaunt |
Difference |
| Before |
1x1 =
1 u |
4x1 =
4 u |
3x1 =
3 u |
| Change 1 |
+ 9 |
+ 9 |
|
| After |
|
49 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
7x1 =
7 u |
10x1 =
10 u |
3x1 =
3 u |
The age difference between Riordan and his grandaunt remains unchanged.
LCM of 3 and 3 is 3.
4 u + 9 = 49
4 u = 49 - 9
4 u = 40
1 u = 40 ÷ 4 = 10
Number of years' time when Riordan's age will be
710 that of his grandaunt's age
= 7 u - 1 u
= 6 u
= 6 x 10
= 60
Answer(s): 60
