Answer:
5.52
Hope this helped!
Step-by-step explanation:
Let c = cost of a spoon
3c = cost of knife
9c + 12(3c) = 82.80
9c + 36c = 82.80
c = 82.80/45
= 1.84
cost of 1 knife = 1.84 x 3
= $5.52 check
9*1.84 + 12*5.52 = 82.80
