Shiyun will be 72 years old in 12 years' time. Now, Rachel's age is 56 of Shiyun's age. What was Rachel's age when she was 4 years more than 75% of Shiyun's age?
| |
Rachel |
Shiyun |
Difference |
| Before |
3 p + 4 |
4 p |
1 p - 4 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
5 u |
6 u |
1 u |
| Change 2 |
+ 12 |
+ 12 |
|
| After |
5 u + 12 |
72 |
|
Shiyun's age in 12 years' time = 6 u + 12
6 u + 12 = 72
6 u = 72 - 12
6 u = 60
1 u = 60 ÷ 6 = 10
Difference between Shiyun's age and Rachel's age
= 1 u
= 10
75% =
75100 =
34 Difference in Shiyun's age and Rachel's age at first
= 4 p - (3 p + 4)
= 1 p - 4
The difference in age between Shiyun and Rachel remains unchanged.
1 p - 4 = 10
1 p = 10 + 4 = 14
Rachel's age when she was 4 years more than 75% of Shiyun's age
= 3 p + 4
= 3 x 14 + 4
= 42 + 4
= 46
Answer(s): 46
