The amount of gasoline at a gas station changes from 85,319.61 gallons to 83,572.41 gallons over a day. What rational number represents the average change in the amount of gasoline per hour.

Haley buys 9 pounds of apples for $3. how many pounds of apples can she buy for $1?

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.

What is the value of x when x + 7 = 21?