Mr Harry is 2 times as old as his cousin, Mark. 9 years ago, the ratio in the age of Mr Harry and Mark was 7 : 2. Find Mr Harry's current age.
| |
Mr Harry |
Mark |
Difference |
| Before |
7x1 =
7 u |
2x1 =
2 u |
5x1 =
5 u |
| Change |
+ 9 |
+ 9 |
|
| After |
2x5 =
10 u |
1x5 =
5 u |
1x5 =
5 u |
The difference in the age of Mr Harry and Mark at first and in the end remains unchanged. Make the difference in age the same. LCM of 5 and 1 is 5.
The increase in the age of Mr Harry and Mark is the same.
Increase in Mark's age
= 5 u - 2 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Mr Harry's current age
= 10 u
= 10 x 3
= 30
Answer(s): 30
