Adam and Bryan have a total of $219.
Adam spends
13 of his money and
Bryan spends
16 of his money.
They spend $38 altogether.
- How much does Adam have at first?
- How much does Bryan have in the end?
|
Adam |
Bryan |
Before |
3 u |
6 p |
Change |
- 1 u |
- 1 p |
After |
2 u |
5 p |
(a)
Amount that Adam has at first = 3 u
Amount that Bryan has at first = 6 p
Total amount that they have = 3 u + 6 p = 219 --- (1)
Total amount that they spend = 1 u + 1 p = 38 --- (2)
(2)
x 6 6 u + 6 p = 228 --- (3)
(3) - (1)
(6 u + 6 p) - (3 u + 6 p) = 228 - 219
6 u + 6 p - 3 u - 6 p = 228 - 219
6 u - 3 u + 6 p - 6 p = 9
6 u - 3 u = 9
3 u = 9
1 u = 9 ÷ 3 = 3
Substitute 1 u = 3 into (1).
3 u + 6 p = 219
3 x 3 + 6 p = 219
9 + 6 p = 219
6 p = 219 - 9 = 210
1 p = 210 ÷ 6 = 35
Amount that Adam has at first
= 3 u
= 3 x 3
= $9
(b)
Amount that Bryan has in the end
= 6 p - 1 p
= 5 p
= 5 x 35
= $175
Answer(s): (a) $9; (b) $175