Adam was 5 times as old as Bryan 5 years ago.
Their total present age is 40 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 |
5 years ago |
5 u |
1 u |
6 u |
Change |
+ 5 |
+ 5 |
+ 10 |
Present |
5 u + 5 |
1 u + 5 |
40 |
(a)
Total age of Adam and Bryan 5 years ago
= 40 - 10
= 30
5 years ago
Adam's age = 5 u
Bryan's age = 1 u
Total age of Adam and Bryan = 6 u
6 u + 10 = 40
6 u = 40 - 10 = 30
1 u = 30 ÷ 6 = 5
Adam's age now
= 5 u + 5
= 5 x 5 + 5
= 25 + 5
= 30
(b)
Number of years that Adam is older than Bryan
= 5 u - 1 u
= 4 u
= 4 x 5
= 20
(c)
Bryan's age in 30 years' time
= 1 u + 5 + 30
= 5 + 5 + 30
= 40
Answer(s): (a) 30; (b) 20; (c) 40