Bryan and Adam have a total of $167.
Bryan spends
13 of his money and
Adam spends
17 of his money.
They spend $29 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
3 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
2 u |
6 p |
(a)
Amount that Bryan has at first = 3 u
Amount that Adam has at first = 7 p
Total amount that they have = 3 u + 7 p = 167 --- (1)
Total amount that they spend = 1 u + 1 p = 29 --- (2)
(2)
x 7 7 u + 7 p = 203 --- (3)
(3) - (1)
(7 u + 7 p) - (3 u + 7 p) = 203 - 167
7 u + 7 p - 3 u - 7 p = 203 - 167
7 u - 3 u + 7 p - 7 p = 36
7 u - 3 u = 36
4 u = 36
1 u = 36 ÷ 4 = 9
Substitute 1 u = 9 into (1).
3 u + 7 p = 167
3 x 9 + 7 p = 167
27 + 7 p = 167
7 p = 167 - 27 = 140
1 p = 140 ÷ 7 = 20
Amount that Bryan has at first
= 3 u
= 3 x 9
= $27
(b)
Amount that Adam has in the end
= 7 p - 1 p
= 6 p
= 6 x 20
= $120
Answer(s): (a) $27; (b) $120