Adam was 4 times as old as Bryan 25 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 20 years' time?
|
Adam |
Bryan |
Total |
25 years ago |
4 u |
1 u |
5 u |
Change |
+ 25 |
+ 25 |
+ 50 |
Present |
4 u + 25 |
1 u + 25 |
80 |
(a)
Total age of Adam and Bryan 25 years ago
= 80 - 50
= 30
25 years ago
Adam's age = 4 u
Bryan's age = 1 u
Total age of Adam and Bryan = 5 u
5 u + 50 = 80
5 u = 80 - 50 = 30
1 u = 30 ÷ 5 = 6
Adam's age now
= 4 u + 25
= 4 x 6 + 25
= 24 + 25
= 49
(b)
Number of years that Adam is older than Bryan
= 4 u - 1 u
= 3 u
= 3 x 6
= 18
(c)
Bryan's age in 20 years' time
= 1 u + 25 + 20
= 6 + 25 + 20
= 51
Answer(s): (a) 49; (b) 18; (c) 51