Bryan was 4 times as old as Adam 10 years ago.
Their total present age is 90 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 |
10 years ago |
4 u |
1 u |
5 u |
Change |
+ 10 |
+ 10 |
+ 20 |
Present |
4 u + 10 |
1 u + 10 |
90 |
(a)
Total age of Bryan and Adam 10 years ago
= 90 - 20
= 70
10 years ago
Bryan's age = 4 u
Adam's age = 1 u
Total age of Bryan and Adam = 5 u
5 u + 20 = 90
5 u = 90 - 20 = 70
1 u = 70 ÷ 5 = 14
Bryan's age now
= 4 u + 10
= 4 x 14 + 10
= 56 + 10
= 66
(b)
Number of years that Bryan is older than Adam
= 4 u - 1 u
= 3 u
= 3 x 14
= 42
(c)
Adam's age in 10 years' time
= 1 u + 10 + 10
= 14 + 10 + 10
= 34
Answer(s): (a) 66; (b) 42; (c) 34