Adam is 20 years old. The total age of Adam and Bryan is 76 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 |
20 |
56 |
76 |
36 |
Bryan's age
= 76 - 20
= 56
Difference in the age between Adam and Bryan
= 56 - 20
= 36
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 = 36
1 u = 36 ÷ 3 = 12
Adam's age then = 1 u = 12
Adam's age now = 20
Number of years ago
= 20 - 12
= 8
Answer(s): 8
