Mr Andy is 2 times as old as his son, Fred. 12 years ago, the ratio in the age of Mr Andy and Fred was 10 : 3. Find Mr Andy's current age.
| |
Mr Andy |
Fred |
Difference |
| Before |
10x1 =
10 u |
3x1 =
3 u |
7x1 =
7 u |
| Change |
+ 12 |
+ 12 |
|
| After |
2x7 =
14 u |
1x7 =
7 u |
1x7 =
7 u |
The difference in the age of Mr Andy and Fred 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 Andy and Fred is the same.
Increase in Fred's age
= 7 u - 3 u
= 4 u
4 u = 12
1 u = 12 ÷ 4 = 3
Mr Andy's current age
= 14 u
= 14 x 3
= 42
Answer(s): 42
