Bryan is 30 years old. The total age of Bryan and Adam is 70 years. How many years ago was the ratio of Bryan's age to Adam's age 1 : 3?
|
Bryan |
Adam |
Total |
Difference |
Before |
1 u |
3 u |
|
2 u |
Change |
+ ? |
+ ? |
|
|
After |
30 |
40 |
70 |
10 |
Adam's age
= 70 - 30
= 40
Difference in the age between Bryan and Adam
= 40 - 30
= 10
To find the number of years ago for the ratio of Bryan's age to Adam's age to be 1 : 3.
Bryan's age = 1 u
Adam's age = 3 u
Difference in the age
= 3 u - 1 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Bryan's age then = 1 u = 5
Bryan's age now = 30
Number of years ago
= 30 - 5
= 25
Answer(s): 25