Adam was 4 times as old as Bryan 10 years ago.
Their total present age is 75 years now.
- How old is Adam now?
- How many years is Adam older than Bryan?
- How old is Bryan in 20 years' time?
|
Adam |
Bryan |
Total |
10 years ago |
4 u |
1 u |
5 u |
Change |
+ 10 |
+ 10 |
+ 20 |
Present |
4 u + 10 |
1 u + 10 |
75 |
(a)
Total age of Adam and Bryan 10 years ago
= 75 - 20
= 55
10 years ago
Adam's age = 4 u
Bryan's age = 1 u
Total age of Adam and Bryan = 5 u
5 u + 20 = 75
5 u = 75 - 20 = 55
1 u = 55 ÷ 5 = 11
Adam's age now
= 4 u + 10
= 4 x 11 + 10
= 44 + 10
= 54
(b)
Number of years that Adam is older than Bryan
= 4 u - 1 u
= 3 u
= 3 x 11
= 33
(c)
Bryan's age in 20 years' time
= 1 u + 10 + 20
= 11 + 10 + 20
= 41
Answer(s): (a) 54; (b) 33; (c) 41