ABC company charges its customers according to their usage of electricity. One rate it charges commercial user is as follows: a monthly customer charge of $6.00, $0.04 energy charge per kwh for the first 1,000 kwh, $0.02 energy charge per kwh in excess of 1,000 kwh. What is the total charge for using 3000 kwh? How many kwh were used if the total charge is $200