Fill in the blanks.
Adam is 79 years old and
Bryan is 39 years old.
- Difference in their age now = _____
- Difference in their age when Adam was thrice the age of Bryan = _____ u
- In how many years' before was Adam thrice the age of Bryan?
- How old was Adam when he was thrice the age of Bryan?
|
Adam |
Bryan |
Difference |
Before |
3 u |
1 u |
2 u |
Change |
+ ? |
+ ? |
|
After |
79 |
39 |
40 |
(a)
Change X times into units.
Difference in their age now
= 79 - 39
= 40
(b)
Difference in the age when Adam is thrice the age of Bryan
= 3 u - 1 u
= 2 u
(c)
2 u = 40
1 u = 40 ÷ 2 = 20
Number of years before when Adam was thrice the age of Bryan
= 39 - 1 u
= 39 - 20
= 19
(d)
Adam's age before when he was thrice the age of Bryan
= 3 u
= 3 x 20
= 60
Answer(s): (a) 40; (b) 2; (c) 19; (d) 60