Bryan is 25 years old. The total age of Bryan and Adam is 78 years. How many years ago was the ratio of Bryan's age to Adam's age 3 : 7?
|
Bryan |
Adam |
Total |
Difference |
Before |
3 u |
7 u |
|
4 u |
Change |
+ ? |
+ ? |
|
|
After |
25 |
53 |
78 |
28 |
Adam's age
= 78 - 25
= 53
Difference in the age between Bryan and Adam
= 53 - 25
= 28
To find the number of years ago for the ratio of Bryan's age to Adam's age to be 3 : 7.
Bryan's age = 3 u
Adam's age = 7 u
Difference in the age
= 7 u - 3 u
= 4 u
4 u = 28
1 u = 28 ÷ 4 = 7
Bryan's age then = 3 u = 21
Bryan's age now = 25
Number of years ago
= 25 - 21
= 4
Answer(s): 4