Paul's age is
14 of his grandmother's. His grandmother will be 54 years old in 14 years' time. In how many years' time will Paul's age be
23 that of his grandmother's?
| |
Paul |
His grandmother |
Difference |
| Before |
1x1 =
1 u |
4x1 =
4 u |
3x1 =
3 u |
| Change 1 |
+ 14 |
+ 14 |
|
| After |
|
54 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
2x3 =
6 u |
3x3 =
9 u |
1x3 =
3 u |
The age difference between Paul and his grandmother remains unchanged.
LCM of 3 and 1 is 3.
4 u + 14 = 54
4 u = 54 - 14
4 u = 40
1 u = 40 ÷ 4 = 10
Number of years' time when Paul's age will be
23 that of his grandmother's age
= 6 u - 1 u
= 5 u
= 5 x 10
= 50
Answer(s): 50
