Penelope and Xandra had $109 at first. Penelope spent
37 of her money and Xandra spent
34 of her money. Given that they had $34 left, how much did Penelope have at first?
| |
Penelope |
Xandra |
Total |
| Before |
7 u |
4 p |
$109 |
| Change |
- 3 u |
- 3 p |
|
| After |
4 u |
1 p |
$34 |
7 u + 4 p = 109 --- (1)
4 u + 1 p = 34 --- (2)
(2) x 4 16 u + 4 p = 136 --- (3)
(3) - (1)
16 u - 7 u = 136 - 109
9 u = 27
1 u = 27 ÷ 9 = 3
Amount that Penelope had at first
= 7 u
= 7 x 3
= $21
Answer(s): $21
