Richard works at an icecream shop, regular cones get two scoops of icecream; large gets three scoops of icecream. richard scoops 234 regular cones and 156 large cones. one scoop of icecream is 3 ounces. a tub of icecream weighs 10 pounds. how many tubs of icream did richard use?

The total number of scoops of ice cream that Richard got from the tub is,
   (234 regular cones) x (2 scoops / 1 regular cone) + (156 large cones) x (2 scoops / 1 large cone) = 936 scoops

Given that each scoop weighs 3 ounces, the total weight of the ice cream is 2808 ounces. For the number of tubs,
          (2808 ounces) x (1 lb / 16 ounces) x (1 tub /10 lb) = 17.55
Thus, the answer is 18.