Adam was 4 times as old as Bryan 30 years ago.
Their total present age is 80 years now.
- How old is Adam now?
- How many years is Adam older than Bryan?
- How old is Bryan in 30 years' time?
|
Adam |
Bryan |
Total |
30 years ago |
4 u |
1 u |
5 u |
Change |
+ 30 |
+ 30 |
+ 60 |
Present |
4 u + 30 |
1 u + 30 |
80 |
(a)
Total age of Adam and Bryan 30 years ago
= 80 - 60
= 20
30 years ago
Adam's age = 4 u
Bryan's age = 1 u
Total age of Adam and Bryan = 5 u
5 u + 60 = 80
5 u = 80 - 60 = 20
1 u = 20 ÷ 5 = 4
Adam's age now
= 4 u + 30
= 4 x 4 + 30
= 16 + 30
= 46
(b)
Number of years that Adam is older than Bryan
= 4 u - 1 u
= 3 u
= 3 x 4
= 12
(c)
Bryan's age in 30 years' time
= 1 u + 30 + 30
= 4 + 30 + 30
= 64
Answer(s): (a) 46; (b) 12; (c) 64