H + c = 605
c = h + 55
h + h + 55 = 605
2h + 55 = 605
2h = 605 - 55
2h = 550
h = 550/2
h = 275 <== there were 275 hamburgers sold on Friday
c = h + 55
c = 275 + 55
C = 330...there were 330 cheeseburgers sold on Friday
4 divided by 10.2 equals 0.3921568627
round to the nearest hundredth
0.39