Physics question,please help me and explain in detail,thank you?

electric energy units are often expressed in the form of "kilowatt-hours."a)show that one kilowatt-hour(kWh)is equal to 3.6*10^6J.b)if the typical family f four in the United states uses electric energy at an average rate of 500W, how many kWh would their electric bill be for one month, and c) how many joules would this be?d)at a cost of $0.12 per kWh, what would their monthly bill be in dollars?does the monthly bill depend on the rate at which they use the electric energy?