Bryan was 3 times as old as Adam 15 years ago.
Their total present age is 70 years now.
- How old is Bryan now?
- How many years is Bryan older than Adam?
- How old is Adam in 5 years' time?
|
Bryan |
Adam |
Total |
15 years ago |
3 u |
1 u |
4 u |
Change |
+ 15 |
+ 15 |
+ 30 |
Present |
3 u + 15 |
1 u + 15 |
70 |
(a)
Total age of Bryan and Adam 15 years ago
= 70 - 30
= 40
15 years ago
Bryan's age = 3 u
Adam's age = 1 u
Total age of Bryan and Adam = 4 u
4 u + 30 = 70
4 u = 70 - 30 = 40
1 u = 40 ÷ 4 = 10
Bryan's age now
= 3 u + 15
= 3 x 10 + 15
= 30 + 15
= 45
(b)
Number of years that Bryan is older than Adam
= 3 u - 1 u
= 2 u
= 2 x 10
= 20
(c)
Adam's age in 5 years' time
= 1 u + 15 + 5
= 10 + 15 + 5
= 30
Answer(s): (a) 45; (b) 20; (c) 30