Bryan and Adam have a total of $161.
Bryan spends
14 of his money and
Adam spends
17 of his money.
They spend $38 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 = 161 --- (1)
Total amount that they spend = 1 u + 1 p = 38 --- (2)
(2)
x 7 7 u + 7 p = 266 --- (3)
(3) - (1)
(7 u + 7 p) - (4 u + 7 p) = 266 - 161
7 u + 7 p - 4 u - 7 p = 266 - 161
7 u - 4 u + 7 p - 7 p = 105
7 u - 4 u = 105
3 u = 105
1 u = 105 ÷ 3 = 35
Substitute 1 u = 35 into (1).
4 u + 7 p = 161
4 x 35 + 7 p = 161
140 + 7 p = 161
7 p = 161 - 140 = 21
1 p = 21 ÷ 7 = 3
Amount that Bryan has at first
= 4 u
= 4 x 35
= $140
(b)
Amount that Adam has in the end
= 7 p - 1 p
= 6 p
= 6 x 3
= $18
Answer(s): (a) $140; (b) $18