Adam and Bryan have a total of $86.
Adam spends
12 of his money and
Bryan spends
17 of his money.
They spend $38 altogether.
- How much does Adam have at first?
- How much does Bryan have in the end?
|
Adam |
Bryan |
Before |
2 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
1 u |
6 p |
(a)
Amount that Adam has at first = 2 u
Amount that Bryan has at first = 7 p
Total amount that they have = 2 u + 7 p = 86 --- (1)
Total amount that they spend = 1 u + 1 p = 38 --- (2)
(2)
x 7 7 u + 7 p = 266 --- (3)
(3) - (1)
(7 u + 7 p) - (2 u + 7 p) = 266 - 86
7 u + 7 p - 2 u - 7 p = 266 - 86
7 u - 2 u + 7 p - 7 p = 180
7 u - 2 u = 180
5 u = 180
1 u = 180 ÷ 5 = 36
Substitute 1 u = 36 into (1).
2 u + 7 p = 86
2 x 36 + 7 p = 86
72 + 7 p = 86
7 p = 86 - 72 = 14
1 p = 14 ÷ 7 = 2
Amount that Adam has at first
= 2 u
= 2 x 36
= $72
(b)
Amount that Bryan has in the end
= 7 p - 1 p
= 6 p
= 6 x 2
= $12
Answer(s): (a) $72; (b) $12