Julie will be 74 years old in 20 years' time. Now, Mary's age is 56 of Julie's age. What was Mary's age when she was 3 years more than 75% of Julie's age?
| |
Mary |
Julie |
Difference |
| Before |
3 p + 3 |
4 p |
1 p - 3 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
5 u |
6 u |
1 u |
| Change 2 |
+ 20 |
+ 20 |
|
| After |
5 u + 20 |
74 |
|
Julie's age in 20 years' time = 6 u + 20
6 u + 20 = 74
6 u = 74 - 20
6 u = 54
1 u = 54 ÷ 6 = 9
Difference between Julie's age and Mary's age
= 1 u
= 9
75% =
75100 =
34 Difference in Julie's age and Mary's age at first
= 4 p - (3 p + 3)
= 1 p - 3
The difference in age between Julie and Mary remains unchanged.
1 p - 3 = 9
1 p = 9 + 3 = 12
Mary's age when she was 3 years more than 75% of Julie's age
= 3 p + 3
= 3 x 12 + 3
= 36 + 3
= 39
Answer(s): 39
