Charlie's current age is 7 times as old as Nick's age years ago. Today, Nick's age is Charlie's age the same number of years ago. How old is Nick's age now if the total of their current age is 55?
| |
Charlie |
Nick |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
7 u |
1 p |
7 u - 1 p |
55 |
Total age of Charlie and Nick today = 7 u + 1 p
7 u + 1 p = 55 --- (1)
The difference in Charlie's age and Nick's age remains the same.
7 u - 1 p = 1 p - 1 u
7 u + 1 u = 1 p + 1 p
8 u = 2 p
4 u = 1 p
Substitute 1 p = 4 u into (1).
7 u + 1 p = 55
7 u + 4 u = 55
11 u = 55
1 u = 55 ÷ 11 = 5
Charlie's age now
= 55 - 7 u
= 55 - 7 x 5
= 55 - 35
= 20
Answer(s): 20
