Bryan and Adam have a total of $73.
Bryan spends
13 of his money and
Adam spends
17 of his money.
They spend $15 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
3 u |
7 p |
Change |
- 1 u |
- 1 p |
After |
2 u |
6 p |
(a)
Amount that Bryan has at first = 3 u
Amount that Adam has at first = 7 p
Total amount that they have = 3 u + 7 p = 73 --- (1)
Total amount that they spend = 1 u + 1 p = 15 --- (2)
(2)
x 7 7 u + 7 p = 105 --- (3)
(3) - (1)
(7 u + 7 p) - (3 u + 7 p) = 105 - 73
7 u + 7 p - 3 u - 7 p = 105 - 73
7 u - 3 u + 7 p - 7 p = 32
7 u - 3 u = 32
4 u = 32
1 u = 32 ÷ 4 = 8
Substitute 1 u = 8 into (1).
3 u + 7 p = 73
3 x 8 + 7 p = 73
24 + 7 p = 73
7 p = 73 - 24 = 49
1 p = 49 ÷ 7 = 7
Amount that Bryan has at first
= 3 u
= 3 x 8
= $24
(b)
Amount that Adam has in the end
= 7 p - 1 p
= 6 p
= 6 x 7
= $42
Answer(s): (a) $24; (b) $42