Zara will be 61 years old in 16 years' time. Now, Kylie's age is 45 of Zara's age. What was Kylie's age when she was 2 years less than 90% of Zara's age?
| |
Kylie |
Zara |
Difference |
| Before |
9 p - 2 |
10 p |
1 p + 2 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
4 u |
5 u |
1 u |
| Change 2 |
+ 16 |
+ 16 |
|
| After |
4 u + 16 |
61 |
|
Zara's age in 16 years' time = 5 u + 16
5 u + 16 = 61
5 u = 61 - 16
5 u = 45
1 u = 45 ÷ 5 = 9
Difference between Zara's age and Kylie's age
= 1 u
= 9
90% =
90100 =
910 Difference in Zara's age and Kylie's age at first
= 10 p - (9 p - 2)
= 1 p + 2
The difference in age between Zara and Kylie remains unchanged.
1 p + 2 = 9
1 p = 9 - 2 = 7
Kylie's age when she was 2 years less than 90% of Zara's age
= 9 p - 2
= 9 x 7 - 2
= 63 - 2
= 61
Answer(s): 61
