Ian's age is
23 his brother's age now. 15 years ago, his age was
13 that of his brother's. How old is Ian now?
| |
Ian |
Ian's brother |
Difference |
| Before |
1x1 =
1 u |
3x1 =
3 u |
2x1 =
2 u |
| Change |
+ 15 |
+ 15 |
|
| After |
2x2 =
4 u |
3x2 =
6 u |
1x2 =
2 u |
The difference in the age between Ian and Ian's brother remains unchanged. Make the difference in age the same. LCM of 2 and 1 is 2.
Increase in the age of Ian
= 4 u - 1 u
= 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Ian's age now
= 4 u
= 4 x 5
= 20
Answer(s): 20
