Adam and Bryan have a total of $88.
Adam spends
12 of his money and
Bryan spends
17 of his money.
They spend $14 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 = 88 --- (1)
Total amount that they spend = 1 u + 1 p = 14 --- (2)
(2)
x 7 7 u + 7 p = 98 --- (3)
(3) - (1)
(7 u + 7 p) - (2 u + 7 p) = 98 - 88
7 u + 7 p - 2 u - 7 p = 98 - 88
7 u - 2 u + 7 p - 7 p = 10
7 u - 2 u = 10
5 u = 10
1 u = 10 ÷ 5 = 2
Substitute 1 u = 2 into (1).
2 u + 7 p = 88
2 x 2 + 7 p = 88
4 + 7 p = 88
7 p = 88 - 4 = 84
1 p = 84 ÷ 7 = 12
Amount that Adam has at first
= 2 u
= 2 x 2
= $4
(b)
Amount that Bryan has in the end
= 7 p - 1 p
= 6 p
= 6 x 12
= $72
Answer(s): (a) $4; (b) $72