Vanessa will be 78 years old in 18 years' time. Now, Jade's age is 34 of Vanessa's age. What was Jade's age when she was 13 years less than 90% of Vanessa's age?
| |
Jade |
Vanessa |
Difference |
| Before |
9 p - 13 |
10 p |
1 p + 13 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
3 u |
4 u |
1 u |
| Change 2 |
+ 18 |
+ 18 |
|
| After |
3 u + 18 |
78 |
|
Vanessa's age in 18 years' time = 4 u + 18
4 u + 18 = 78
4 u = 78 - 18
4 u = 60
1 u = 60 ÷ 4 = 15
Difference between Vanessa's age and Jade's age
= 1 u
= 15
90% =
90100 =
910 Difference in Vanessa's age and Jade's age at first
= 10 p - (9 p - 13)
= 1 p + 13
The difference in age between Vanessa and Jade remains unchanged.
1 p + 13 = 15
1 p = 15 - 13 = 2
Jade's age when she was 13 years less than 90% of Vanessa's age
= 9 p - 13
= 9 x 2 - 13
= 18 - 13
= 5
Answer(s): 5
