In your problem which ask to calculate how much does it cost to operate a light for an hour is the current in a lamp is 120V and has a current of 2.4 A. The cost of electrical energy is $0.09 per kilowatt hours, so with that dat itself, the possible in terms of cents is actually 3 cents
The pricing of the boxes seems to be consistently 2.40 per box. Ethan's cost is .. 52.80 = 2.40 * (# of boxes) .. 52.80/2.40 = (# of boxes) .. 22 = # of boxes
