Bryan is 20 years old. The total age of Bryan and Adam is 80 years. How many years' time will the ratio of Bryan's age to Adam's age be 3 : 5?
|
Bryan |
Adam |
Total |
Difference |
Before |
20 |
60 |
80 |
40 |
Change |
+ ? |
+ ? |
|
|
After |
3 u |
5 u |
|
2 u |
Adam's age
= 80 - 20
= 60
Difference in the age between Bryan and Adam
= 60 - 20
= 40
Difference in the age between Bryan and Adam in units
= 5 u - 3 u
= 2 u
2 u = 40
1 u = 40 ÷ 2 = 20
Bryan's age now = 20
Bryan's age after = 3 u = 3 x 20 = 60
Number of years' time
= 60 - 20
= 40
Answer(s): 40