Mr Riordan is 2 times as old as his cousin, Jeremy. 20 years ago, the ratio in the age of Mr Riordan and Jeremy was 9 : 2. Find Jeremy's current age.
| |
Mr Riordan |
Jeremy |
Difference |
| Before |
9x1 =
9 u |
2x1 =
2 u |
7x1 =
7 u |
| Change |
+ 20 |
+ 20 |
|
| After |
2x7 =
14 u |
1x7 =
7 u |
1x7 =
7 u |
The difference in the age of Mr Riordan and Jeremy at first and in the end remains unchanged. Make the difference in age the same. LCM of 7 and 1 is 7.
The increase in the age of Mr Riordan and Jeremy is the same.
Increase in Jeremy's age
= 7 u - 2 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Jeremy's current age
= 7 u
= 7 x 4
= 28
Answer(s): 28
