52. How much energy in kilowatthours is required to keep a 230-W oil-burner motor running 12 h a week for 5 months? (Use 41 3 weeks 1 month.)

54. How much does it cost to use a 30-W radio for 3 h at 9 per kilowatthour?

56. a. At 9 per kilowatthour, how long can one play a 250-W color television for $1?

b. For $1, how long can one use a 4.8-kW dryer?

c. Compare the results of parts (a) and (b), and comment on the effect of the wattage level on the relative cost of using an appliance.

58. What is the total cost of using the following at 9 per kilowatthour? 110-W stereo set for 4 h 1200-W projector for 20 min 60-W tape recorder for 1.5 h 150-W color television set for 3 h 45 min