Betty will be 87 years old in 3 years' time. Now, Kimberly's age is 56 of Betty's age. What was Kimberly's age when she was 4 years more than 75% of Betty's age?
| |
Kimberly |
Betty |
Difference |
| Before |
3 p + 4 |
4 p |
1 p - 4 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
5 u |
6 u |
1 u |
| Change 2 |
+ 3 |
+ 3 |
|
| After |
5 u + 3 |
87 |
|
Betty's age in 3 years' time = 6 u + 3
6 u + 3 = 87
6 u = 87 - 3
6 u = 84
1 u = 84 ÷ 6 = 14
Difference between Betty's age and Kimberly's age
= 1 u
= 14
75% =
75100 =
34 Difference in Betty's age and Kimberly's age at first
= 4 p - (3 p + 4)
= 1 p - 4
The difference in age between Betty and Kimberly remains unchanged.
1 p - 4 = 14
1 p = 14 + 4 = 18
Kimberly's age when she was 4 years more than 75% of Betty's age
= 3 p + 4
= 3 x 18 + 4
= 54 + 4
= 58
Answer(s): 58
