Answer:
roses were $1 each and chocolates were $4 per box
Step-by-step explanation:
let Cost of 1 rose = "R" and Cost of 1 box of chocolate = "C"
First day: cost of 20 roses + cost of 15 chocolate = $80,
or...
20R + 15C = 80 (divide both sides by 5)
4R + 3C = 16 ------------(eq 1)
Second day: cost of 40 roses + cost of 20 chocolate = $120,
or...
40R + 20C = 120 (divide both sides by 10)
4R + 2C = 12 ------------(eq 2)
by elimination, (eq 1) - (eq 2)
(4R + 3C) - (4R + 2C) = 16 - 12
4R + 3C - 4R - 2C = 4
C = 4 (substitute this back into eq 1)
4R + 3(4) = 16
4R + 12 = 16
4R = 16 - 12
4R = 4
R = 1
Hence roses were $1 each and chocolates were $4 per box
