Adam is 4 times as old as Bryan now.
In 10 years time, their total age is 70 years.
How old is Adam now?
- How old is Bryan now?
- How many years is Bryan younger than Adam?
- How old was Adam 21 years ago?
|
Adam |
Bryan |
Total |
Now |
4 u |
1 u |
5 u |
Change |
+ 10 |
+ 10 |
+ 20 |
10 years later |
4 u + 10 |
1 u + 10 |
70 |
(a)
Total age of Adam and Bryan now
= 70 - 20
= 50
Now
Adam's age = 4 u
Bryan's age = 1 u
Total age of Adam and Bryan = 5 u
5 u = 50
1 u = 50 ÷ 5 = 10
Bryan's age now
= 1 u
= 10
(b)
Number of years that Bryan is younger than Adam
= 4 u - 1 u
= 3 u
= 3 x 10
= 30
(c)
Adam's age 21 years' ago
= 4 u - 21
= 4 x 10 - 21
= 40 - 21
= 19
Answer(s): (a) 10; (b) 30; (c) 19