The age of Riordan is
47 of Tommy's age. 32 years later, the ratio of Riordan's age to Tommy's age is 4 : 5. How old is Tommy at first?
|
Riordan |
Tommy |
Difference |
Before |
4 u |
7 u |
3 u |
Change |
+ 32 |
+ 32 |
|
After |
4x3 = 12 u |
5x3 = 15 u |
1x3 = 3 u |
The difference in the age between Riordan and Tommy at first and in the end remains unchanged. Make the difference in the age between Riordan and Tommy the same. LCM of 3 and 1 is 3.
Increase in Riordan's age
= 12 u - 4 u
= 8 u
8 u = 32
1 u = 32 ÷ 8 = 4
Tommy's age at first
= 7 u
= 7 x 4
= 28
Answer(s): 28