Xuan's mother is 4 times as old as her. Xuan will be 14 years old in 8 years' time. In how many years' time will Xuan's age be 60% that of her mother's?
| |
Xuan's mother |
Xuan |
Difference |
Before
(now) |
4x2 =
8 u |
1x2 =
2 u |
3x2 =
6 u |
| Change 1 |
+ 8 |
+ 8 |
|
| After 1 |
|
14 |
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
5x3 =
15 u |
3x3 =
9 u |
2x3 =
6 u |
60% =
60100 =
35 Xuan's mother : Xuan = 5 : 3
The difference in age between Xuan's mother and Xuan always remains the same. Make the difference in age between Xuan's mother and Xuan the same. LCM of 3 and 2 is 6.
2 u + 8 = 14
2 u = 14 - 8
2 u = 6
1 u = 6 ÷ 2 = 3
Number of years' time when Xuan's age will be 60% that of her mother's
= 15 u - 32
= 15 x 3 - 32
= 45 - 32
= 13
Answer(s): 13
