Risa will be 51 years old in 3 years' time. Now, Esther's age is 56 of Risa's age. What was Esther's age when she was 2 years less than 80% of Risa's age?
| |
Esther |
Risa |
Difference |
| Before |
4 p - 2 |
5 p |
1 p + 2 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
5 u |
6 u |
1 u |
| Change 2 |
+ 3 |
+ 3 |
|
| After |
5 u + 3 |
51 |
|
Risa's age in 3 years' time = 6 u + 3
6 u + 3 = 51
6 u = 51 - 3
6 u = 48
1 u = 48 ÷ 6 = 8
Difference between Risa's age and Esther's age
= 1 u
= 8
80% =
80100 =
45 Difference in Risa's age and Esther's age at first
= 5 p - (4 p - 2)
= 1 p + 2
The difference in age between Risa and Esther remains unchanged.
1 p + 2 = 8
1 p = 8 - 2 = 6
Esther's age when she was 2 years less than 80% of Risa's age
= 4 p - 2
= 4 x 6 - 2
= 24 - 2
= 22
Answer(s): 22
