Question

casey is making a flower arrangement with roses(r) and carnations(c). the cost of each rose is $0.50 and the cost of each carnation is $0.10. the arrangement has a total of 80 flowers and the flower cost was $20. how many of each flower did casey put in her arrangement?

Answer 1

r + c = 80....r = 80 - c
0.50r + 0.10c = 20

0.50(80 - c) + 0.10c = 20
40 - 0.50c + 0.10c = 20
-0.50c + 0.10c = 20 - 40
-0.40c = -20
c = -20/0.40
c = 50 <=== she put in 50 carnations

r = 80 - c
r = 80 - 50
r = 30 <=== she put in 30 roses