Adam and Bryan have a total of $299.
Adam spends
14 of his money and
Bryan spends
17 of his money.
They spend $44 altogether.
- How much does Adam have at first?
- How much does Bryan have in the end?
|
Adam |
Bryan |
Before |
4 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
3 u |
6 p |
(a)
Amount that Adam has at first = 4 u
Amount that Bryan has at first = 7 p
Total amount that they have = 4 u + 7 p = 299 --- (1)
Total amount that they spend = 1 u + 1 p = 44 --- (2)
(2)
x 7 7 u + 7 p = 308 --- (3)
(3) - (1)
(7 u + 7 p) - (4 u + 7 p) = 308 - 299
7 u + 7 p - 4 u - 7 p = 308 - 299
7 u - 4 u + 7 p - 7 p = 9
7 u - 4 u = 9
3 u = 9
1 u = 9 ÷ 3 = 3
Substitute 1 u = 3 into (1).
4 u + 7 p = 299
4 x 3 + 7 p = 299
12 + 7 p = 299
7 p = 299 - 12 = 287
1 p = 287 ÷ 7 = 41
Amount that Adam has at first
= 4 u
= 4 x 3
= $12
(b)
Amount that Bryan has in the end
= 7 p - 1 p
= 6 p
= 6 x 41
= $246
Answer(s): (a) $12; (b) $246