Bryan is 21 years old. The total age of Bryan and Adam is 76 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 |
21 |
55 |
76 |
34 |
Adam's age
= 76 - 21
= 55
Difference in the age between Bryan and Adam
= 55 - 21
= 34
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 = 34
1 u = 34 ÷ 2 = 17
Bryan's age then = 1 u = 17
Bryan's age now = 21
Number of years ago
= 21 - 17
= 4
Answer(s): 4