Adam is 30 years old. The total age of Adam and Bryan is 84 years. How many years ago was the ratio of Adam's age to Bryan's age 3 : 7?
|
Adam |
Bryan |
Total |
Difference |
Before |
3 u |
7 u |
|
4 u |
Change |
+ ? |
+ ? |
|
|
After |
30 |
54 |
84 |
24 |
Bryan's age
= 84 - 30
= 54
Difference in the age between Adam and Bryan
= 54 - 30
= 24
To find the number of years ago for the ratio of Adam's age to Bryan's age to be 3 : 7.
Adam's age = 3 u
Bryan's age = 7 u
Difference in the age
= 7 u - 3 u
= 4 u
4 u = 24
1 u = 24 ÷ 4 = 6
Adam's age then = 3 u = 18
Adam's age now = 30
Number of years ago
= 30 - 18
= 12
Answer(s): 12