Adam is 57 years old.
Bryan is 21 years old.
A few years ago, Adam was 3 times as old as Bryan.
- How many years ago was Adam 3 times as old as Bryan?
- How old was Adam then?
|
Adam |
Bryan |
Difference |
Before |
3 u |
1 u |
2 u |
Change |
+ ? |
+ ? |
|
After |
57 |
21 |
36 |
(a)
For Adam to be 3 times as old as Bryan,
Bryan's age = 1 u
Adam's age = 3 u
Difference in their age
= 3 u - 1 u
= 2 u
Age difference between Adam and Bryan
= 57 - 21
= 36
2 u = 36
1 u = 36 ÷ 2 = 18
Number of years' ago that Adam was 3 times as old as Bryan
= 21 - 18
= 3
(b)
Adam's age 3 years ago
= 3 u
= 3 x 18
= 54
Answer(s): (a) 3; (b) 54