Ken's age is
13 of his grandaunt's. His grandaunt will be 49 years old in 7 years' time. In how many years' time will Ken's age be
35 that of his grandaunt's?
| |
Ken |
His grandaunt |
Difference |
| Before |
1x1 =
1 u |
3x1 =
3 u |
2x1 =
2 u |
| Change 1 |
+ 7 |
+ 7 |
|
| After |
|
49 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
3x1 =
3 u |
5x1 =
5 u |
2x1 =
2 u |
The age difference between Ken and his grandaunt remains unchanged.
LCM of 2 and 2 is 2.
3 u + 7 = 49
3 u = 49 - 7
3 u = 42
1 u = 42 ÷ 3 = 14
Number of years' time when Ken's age will be
35 that of his grandaunt's age
= 3 u - 1 u
= 2 u
= 2 x 14
= 28
Answer(s): 28
