Brandon's current age is 7 times as old as Ryan's age years ago. Today, Ryan's age is Brandon's age the same number of years ago. How old is Ryan's age now if the total of their current age is 55?
| |
Brandon |
Ryan |
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 Brandon and Ryan today = 7 u + 1 p
7 u + 1 p = 55 --- (1)
The difference in Brandon's age and Ryan'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
Brandon's age now
= 55 - 7 u
= 55 - 7 x 5
= 55 - 35
= 20
Answer(s): 20
