Bryan is 10 years old. The total age of Bryan and Adam is 70 years. How many years' time will the ratio of Bryan's age to Adam's age be 2 : 7?
|
Bryan |
Adam |
Total |
Difference |
Before |
10 |
60 |
70 |
50 |
Change |
+ ? |
+ ? |
|
|
After |
2 u |
7 u |
|
5 u |
Adam's age
= 70 - 10
= 60
Difference in the age between Bryan and Adam
= 60 - 10
= 50
Difference in the age between Bryan and Adam in units
= 7 u - 2 u
= 5 u
5 u = 50
1 u = 50 ÷ 5 = 10
Bryan's age now = 10
Bryan's age after = 2 u = 2 x 10 = 20
Number of years' time
= 20 - 10
= 10
Answer(s): 10