Bryan and Adam have a total of $228.
Bryan spends
12 of his money and
Adam spends
18 of his money.
They spend $42 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
2 u |
8 p |
Change |
- 1 u |
- 1 p |
After |
1 u |
7 p |
(a)
Amount that Bryan has at first = 2 u
Amount that Adam has at first = 8 p
Total amount that they have = 2 u + 8 p = 228 --- (1)
Total amount that they spend = 1 u + 1 p = 42 --- (2)
(2)
x 8 8 u + 8 p = 336 --- (3)
(3) - (1)
(8 u + 8 p) - (2 u + 8 p) = 336 - 228
8 u + 8 p - 2 u - 8 p = 336 - 228
8 u - 2 u + 8 p - 8 p = 108
8 u - 2 u = 108
6 u = 108
1 u = 108 ÷ 6 = 18
Substitute 1 u = 18 into (1).
2 u + 8 p = 228
2 x 18 + 8 p = 228
36 + 8 p = 228
8 p = 228 - 36 = 192
1 p = 192 ÷ 8 = 24
Amount that Bryan has at first
= 2 u
= 2 x 18
= $36
(b)
Amount that Adam has in the end
= 8 p - 1 p
= 7 p
= 7 x 24
= $168
Answer(s): (a) $36; (b) $168