A companys charge for electricity is 9204 per kilowatthour I

A company\'s charge for electricity is 9.204 per kilowatt-hour. In addition, each monthly bill contains a customer charge of $8.09. If last year\'s bills ranged from a low of $54.12 to a high of $213.07, over what range did usage vary (in kilowatt-hours)?

Solution

The monthly bill for electricity contains a customer charge of $ 8.09. Since the last year’s bills ranged from N$ 54.12 to $ 213.07, the charge for electricity ranged from $( 54.12-8.09) to ($213.07-8.09) i.e. $ 46.03 to $ 204.98. Further, since the charge for electricity is 9.204 c per kwh, the electricity usage varied last year from 46.03*100/9.204 to 204.98*100/9.204 kwh i.e. from 500.11 kwh to 2227.08 kwh ( on rounding ff to 2 decimal places).