Four years ago, Jack's age was 20% of Peter's age. Ten years from their current age, Jack's age will be 37.5% of Peter's age. How many years is Peter older than Jack?
| |
Jack |
Peter |
Difference |
| Before |
1x5 =
5 u |
5x5 =
25 u |
4x5 =
20 u |
| Change |
+ 4
+ 10 |
+ 4
+ 10 |
|
| After |
3x4 =
12 u |
8x4 =
32 u |
5x4 =
20 u |
20% =
20100 =
15 37.5% =
3751000 =
38The difference in the ages between Jack and Peter remains unchanged. Make the difference the same. LCM of 4 and 5 is 20.
Increase in Jack's age
= 12 u - 5 u
= 7 u
7 u = 4 + 10
7 u = 14
1 u = 14 ÷ 7 = 2
Number of years that Peter is older than Jack
= 25 u - 5 u
= 20 u
= 20 x 2
= 40
Answer(s): 40
