Adam is 10 years old. The total age of Adam and Bryan is 80 years. How many years' time will the ratio of Adam's age to Bryan's age be 2 : 5?
| |
Adam |
Bryan |
Total |
Difference |
| Before |
10 |
70 |
80 |
60 |
| Change |
+ ? |
+ ? |
|
|
| After |
2 u |
5 u |
|
3 u |
Bryan's age
= 80 - 10
= 70
Difference in the age between Adam and Bryan
= 70 - 10
= 60
Difference in the age between Adam and Bryan in units
= 5 u - 2 u
= 3 u
3 u = 60
1 u = 60 ÷ 3 = 20
Adam's age now = 10
Adam's age after = 2 u = 2 x 20 = 40
Number of years' time
= 40 - 10
= 30
Answer(s): 30
