Adam and Bryan have a total of $252.
Adam spends
15 of his money and
Bryan spends
18 of his money.
They spend $36 altogether.
- How much does Adam have at first?
- How much does Bryan have in the end?
|
Adam |
Bryan |
Before |
5 u |
8 p |
Change |
- 1 u |
- 1 p |
After |
4 u |
7 p |
(a)
Amount that Adam has at first = 5 u
Amount that Bryan has at first = 8 p
Total amount that they have = 5 u + 8 p = 252 --- (1)
Total amount that they spend = 1 u + 1 p = 36 --- (2)
(2)
x 8 8 u + 8 p = 288 --- (3)
(3) - (1)
(8 u + 8 p) - (5 u + 8 p) = 288 - 252
8 u + 8 p - 5 u - 8 p = 288 - 252
8 u - 5 u + 8 p - 8 p = 36
8 u - 5 u = 36
3 u = 36
1 u = 36 ÷ 3 = 12
Substitute 1 u = 12 into (1).
5 u + 8 p = 252
5 x 12 + 8 p = 252
60 + 8 p = 252
8 p = 252 - 60 = 192
1 p = 192 ÷ 8 = 24
Amount that Adam has at first
= 5 u
= 5 x 12
= $60
(b)
Amount that Bryan has in the end
= 8 p - 1 p
= 7 p
= 7 x 24
= $168
Answer(s): (a) $60; (b) $168