Rachel will be 26 years old in 8 years' time. Now, Diana's age is 12 of Rachel's age. What was Diana's age when she was 4 years less than 90% of Rachel's age?
| |
Diana |
Rachel |
Difference |
| Before |
9 p - 4 |
10 p |
1 p + 4 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
1 u |
2 u |
1 u |
| Change 2 |
+ 8 |
+ 8 |
|
| After |
1 u + 8 |
26 |
|
Rachel's age in 8 years' time = 2 u + 8
2 u + 8 = 26
2 u = 26 - 8
2 u = 18
1 u = 18 ÷ 2 = 9
Difference between Rachel's age and Diana's age
= 1 u
= 9
90% =
90100 =
910 Difference in Rachel's age and Diana's age at first
= 10 p - (9 p - 4)
= 1 p + 4
The difference in age between Rachel and Diana remains unchanged.
1 p + 4 = 9
1 p = 9 - 4 = 5
Diana's age when she was 4 years less than 90% of Rachel's age
= 9 p - 4
= 9 x 5 - 4
= 45 - 4
= 41
Answer(s): 41
