Bryan and Adam have a total of $120.
Bryan spends
14 of his money and
Adam spends
17 of his money.
They spend $27 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
4 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
3 u |
6 p |
(a)
Amount that Bryan has at first = 4 u
Amount that Adam has at first = 7 p
Total amount that they have = 4 u + 7 p = 120 --- (1)
Total amount that they spend = 1 u + 1 p = 27 --- (2)
(2)
x 7 7 u + 7 p = 189 --- (3)
(3) - (1)
(7 u + 7 p) - (4 u + 7 p) = 189 - 120
7 u + 7 p - 4 u - 7 p = 189 - 120
7 u - 4 u + 7 p - 7 p = 69
7 u - 4 u = 69
3 u = 69
1 u = 69 ÷ 3 = 23
Substitute 1 u = 23 into (1).
4 u + 7 p = 120
4 x 23 + 7 p = 120
92 + 7 p = 120
7 p = 120 - 92 = 28
1 p = 28 ÷ 7 = 4
Amount that Bryan has at first
= 4 u
= 4 x 23
= $92
(b)
Amount that Adam has in the end
= 7 p - 1 p
= 6 p
= 6 x 4
= $24
Answer(s): (a) $92; (b) $24