Adam and Bryan have a total of $67.
Adam spends
14 of his money and
Bryan spends
17 of his money.
They spend $13 altogether.
- How much does Adam have at first?
- How much does Bryan have in the end?
|
Adam |
Bryan |
Before |
4 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
3 u |
6 p |
(a)
Amount that Adam has at first = 4 u
Amount that Bryan has at first = 7 p
Total amount that they have = 4 u + 7 p = 67 --- (1)
Total amount that they spend = 1 u + 1 p = 13 --- (2)
(2)
x 7 7 u + 7 p = 91 --- (3)
(3) - (1)
(7 u + 7 p) - (4 u + 7 p) = 91 - 67
7 u + 7 p - 4 u - 7 p = 91 - 67
7 u - 4 u + 7 p - 7 p = 24
7 u - 4 u = 24
3 u = 24
1 u = 24 ÷ 3 = 8
Substitute 1 u = 8 into (1).
4 u + 7 p = 67
4 x 8 + 7 p = 67
32 + 7 p = 67
7 p = 67 - 32 = 35
1 p = 35 ÷ 7 = 5
Amount that Adam has at first
= 4 u
= 4 x 8
= $32
(b)
Amount that Bryan has in the end
= 7 p - 1 p
= 6 p
= 6 x 5
= $30
Answer(s): (a) $32; (b) $30