Penelope will be 49 years old in 19 years' time. Now, Nora's age is 23 of Penelope's age. What was Nora's age when she was 4 years less than 80% of Penelope's age?
| |
Nora |
Penelope |
Difference |
| Before |
4 p - 4 |
5 p |
1 p + 4 |
| Change 1 |
+ ? |
+ ? |
|
| After 1 (Now) |
2 u |
3 u |
1 u |
| Change 2 |
+ 19 |
+ 19 |
|
| After |
2 u + 19 |
49 |
|
Penelope's age in 19 years' time = 3 u + 19
3 u + 19 = 49
3 u = 49 - 19
3 u = 30
1 u = 30 ÷ 3 = 10
Difference between Penelope's age and Nora's age
= 1 u
= 10
80% =
80100 =
45 Difference in Penelope's age and Nora's age at first
= 5 p - (4 p - 4)
= 1 p + 4
The difference in age between Penelope and Nora remains unchanged.
1 p + 4 = 10
1 p = 10 - 4 = 6
Nora's age when she was 4 years less than 80% of Penelope's age
= 4 p - 4
= 4 x 6 - 4
= 24 - 4
= 20
Answer(s): 20
