Compute all parts of given question:
Question: A transistor radio operates by means of a 13 V battery that supplies it with 60 mA current. If the cost of the battery is $1.69 and it lasts for 302 h,
Part A: What is the cost per kWh to operate the radio in this manner?
Part B: The same radio, by means of a converter, is plugged into a household circuit by a home owner who pays $0.08 /kW•h.
Part C: What does it now cost to operate the radio for 302 h?
Please explain each step and equations used for above question.