Bryan was 4 times as old as Adam 15 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 |
15 years ago |
4 u |
1 u |
5 u |
Change |
+ 15 |
+ 15 |
+ 30 |
Present |
4 u + 15 |
1 u + 15 |
75 |
(a)
Total age of Bryan and Adam 15 years ago
= 75 - 30
= 45
15 years ago
Bryan's age = 4 u
Adam's age = 1 u
Total age of Bryan and Adam = 5 u
5 u + 30 = 75
5 u = 75 - 30 = 45
1 u = 45 ÷ 5 = 9
Bryan's age now
= 4 u + 15
= 4 x 9 + 15
= 36 + 15
= 51
(b)
Number of years that Bryan is older than Adam
= 4 u - 1 u
= 3 u
= 3 x 9
= 27
(c)
Adam's age in 10 years' time
= 1 u + 15 + 10
= 9 + 15 + 10
= 34
Answer(s): (a) 51; (b) 27; (c) 34