Adam is 3 times as old as Bryan now.
In 4 years time, their total age is 20 years.
How old is Adam now?
- How old is Bryan now?
- How many years is Bryan younger than Adam?
- How old was Adam 4 years ago?
|
Adam |
Bryan |
Total |
Now |
3 u |
1 u |
4 u |
Change |
+ 4 |
+ 4 |
+ 8 |
4 years later |
3 u + 4 |
1 u + 4 |
20 |
(a)
Total age of Adam and Bryan now
= 20 - 8
= 12
Now
Adam's age = 3 u
Bryan's age = 1 u
Total age of Adam and Bryan = 4 u
4 u = 12
1 u = 12 ÷ 4 = 3
Bryan's age now
= 1 u
= 3
(b)
Number of years that Bryan is younger than Adam
= 3 u - 1 u
= 2 u
= 2 x 3
= 6
(c)
Adam's age 4 years' ago
= 3 u - 4
= 3 x 3 - 4
= 9 - 4
= 5
Answer(s): (a) 3; (b) 6; (c) 5