Bryan is 30 years old. The total age of Bryan and Adam is 75 years. How many years ago was the ratio of Bryan's age to Adam's age 1 : 4?
|
Bryan |
Adam |
Total |
Difference |
Before |
1 u |
4 u |
|
3 u |
Change |
+ ? |
+ ? |
|
|
After |
30 |
45 |
75 |
15 |
Adam's age
= 75 - 30
= 45
Difference in the age between Bryan and Adam
= 45 - 30
= 15
To find the number of years ago for the ratio of Bryan's age to Adam's age to be 1 : 4.
Bryan's age = 1 u
Adam's age = 4 u
Difference in the age
= 4 u - 1 u
= 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Bryan's age then = 1 u = 5
Bryan's age now = 30
Number of years ago
= 30 - 5
= 25
Answer(s): 25