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