Bryan was 4 times as old as Adam 30 years ago.
Their total present age is 75 years now.
- How old is Bryan now?
- How many years is Bryan older than Adam?
- How old is Adam in 10 years' time?
|
Bryan |
Adam |
Total |
30 years ago |
4 u |
1 u |
5 u |
Change |
+ 30 |
+ 30 |
+ 60 |
Present |
4 u + 30 |
1 u + 30 |
75 |
(a)
Total age of Bryan and Adam 30 years ago
= 75 - 60
= 15
30 years ago
Bryan's age = 4 u
Adam's age = 1 u
Total age of Bryan and Adam = 5 u
5 u + 60 = 75
5 u = 75 - 60 = 15
1 u = 15 ÷ 5 = 3
Bryan's age now
= 4 u + 30
= 4 x 3 + 30
= 12 + 30
= 42
(b)
Number of years that Bryan is older than Adam
= 4 u - 1 u
= 3 u
= 3 x 3
= 9
(c)
Adam's age in 10 years' time
= 1 u + 30 + 10
= 3 + 30 + 10
= 43
Answer(s): (a) 42; (b) 9; (c) 43