Ivan's current age is 9 times as old as Bryan's age years ago. Today, Bryan's age is Ivan's age the same number of years ago. How old is Bryan's age now if the total of their current age is 28?
| |
Ivan |
Bryan |
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 Ivan and Bryan today = 9 u + 1 p
9 u + 1 p = 28 --- (1)
The difference in Ivan's age and Bryan'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
Ivan's age now
= 28 - 9 u
= 28 - 9 x 2
= 28 - 18
= 10
Answer(s): 10
