Answer: Jan needed 36 jugs to empty 18 gallons of water from a bath tub.
Explanation:
Given : Jan needed to empty 18 gallons of water from a bath tub into jugs that hold 0.5 Gallons of water.
i.e. The amount of water a jug holds = 0.5 gallons
Then , the number of jugs can hold 18 gallons of water will be :-

Hence, Jan needed 36 jugs to empty 18 gallons of water from a bath tub.