Jack's age is
35 his sister's age now. In 15 years' time, his age will be
34 that of his sister's. How old is Jack now?
| |
Jack |
Jack's sister |
Difference |
| Before |
3x1 =
3 u |
5x1 =
5 u |
2x1 =
2 u |
| Change |
+ 15 |
+ 15 |
|
| After |
3x2 =
6 u |
4x2 =
8 u |
1x2 =
2 u |
The difference in the age between Jack and Jack's sister remains unchanged. Make the difference in age the same. LCM of 2 and 1 is 2.
Increase in the age of Jack
= 6 u - 3 u
= 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Jack's age now
= 3 u
= 3 x 5
= 15
Answer(s): 15
