Question

The PA system at North High School requires 400 watts it is switched on. How much would it cost to run 3 hours, at a cost of $0.10 per kilowatt hour? Round to the nearest cent.

Answer 1

Convert 400 watts into kilowatts$=400/1000=0.4kw$

$Cost=0.4\times 3\times0.10=0.12\$$