Riordan's age is
35 his sister's age now. 21 years ago, his age was
14 that of his sister's. How old is Riordan now?
| |
Riordan |
Riordan's sister |
Difference |
| Before |
1x2 =
2 u |
4x2 =
8 u |
3x2 =
6 u |
| Change |
+ 21 |
+ 21 |
|
| After |
3x3 =
9 u |
5x3 =
15 u |
2x3 =
6 u |
The difference in the age between Riordan and Riordan's sister remains unchanged. Make the difference in age the same. LCM of 3 and 2 is 6.
Increase in the age of Riordan
= 9 u - 2 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Riordan's age now
= 9 u
= 9 x 3
= 27
Answer(s): 27
