Charlie's current age is 9 times as old as Valen's age years ago. Today, Valen's age is Charlie's age the same number of years ago. How old is Valen's age now if the total of their current age is 42?
| |
Charlie |
Valen |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
9 u |
1 p |
9 u - 1 p |
42 |
Total age of Charlie and Valen today = 9 u + 1 p
9 u + 1 p = 42 --- (1)
The difference in Charlie's age and Valen'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 = 42
9 u + 5 u = 42
14 u = 42
1 u = 42 ÷ 14 = 3
Charlie's age now
= 42 - 9 u
= 42 - 9 x 3
= 42 - 27
= 15
Answer(s): 15
