Can someone help me please show workings if necessary

Saline iv fluid bags cost $64.20 for 24, 1000 ml bags from one supplier. a new supplier sells 500 ml bags for $2 each. the hospital uses about 10,000, 1000 ml bags each month. nurses report that about half of the bags are more than half full when they are discarded. if you are going to use only one supplier, which size bag provides the best deal, and how much will you save each month? compare the cost of the new supplier to the current one.

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.