Adam is 51 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 |
51 |
21 |
30 |
(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
= 51 - 21
= 30
2 u = 30
1 u = 30 ÷ 2 = 15
Number of years' ago that Adam was 3 times as old as Bryan
= 21 - 15
= 6
(b)
Adam's age 6 years ago
= 3 u
= 3 x 15
= 45
Answer(s): (a) 6; (b) 45