Adam is 18 years old. The total age of Adam and Bryan is 75 years. How many years ago was the ratio of Adam's age to Bryan's age 1 : 4?
|
Adam |
Bryan |
Total |
Difference |
Before |
1 u |
4 u |
|
3 u |
Change |
+ ? |
+ ? |
|
|
After |
18 |
57 |
75 |
39 |
Bryan's age
= 75 - 18
= 57
Difference in the age between Adam and Bryan
= 57 - 18
= 39
To find the number of years ago for the ratio of Adam's age to Bryan's age to be 1 : 4.
Adam's age = 1 u
Bryan's age = 4 u
Difference in the age
= 4 u - 1 u
= 3 u
3 u = 39
1 u = 39 ÷ 3 = 13
Adam's age then = 1 u = 13
Adam's age now = 18
Number of years ago
= 18 - 13
= 5
Answer(s): 5