Tommy's current age is 9 times as old as Dylan's age years ago. Today, Dylan's age is Tommy's age the same number of years ago. How old is Dylan's age now if the total of their current age is 28?
| |
Tommy |
Dylan |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
9 u |
1 p |
9 u - 1 p |
28 |
Total age of Tommy and Dylan today = 9 u + 1 p
9 u + 1 p = 28 --- (1)
The difference in Tommy's age and Dylan's age remains the same.
9 u - 1 p = 1 p - 1 u
9 u + 1 u = 1 p + 1 p
10 u = 2 p
5 u = 1 p
Substitute 1 p = 5 u into (1).
9 u + 1 p = 28
9 u + 5 u = 28
14 u = 28
1 u = 28 ÷ 14 = 2
Tommy's age now
= 28 - 9 u
= 28 - 9 x 2
= 28 - 18
= 10
Answer(s): 10
