A washing machine rated 300 W operates one hour/day. If the cost of a unit is Rs. 3.00 , find the cost of the energy of operate the washing machine for the month of March.

Explanation

Data : P=300 W, Rs. 3.00 Per unit,
t=`1("hour")/("day")xx31` days =31 hours , 1 unit=1 kW`*h`
`=1000 W*h`, cost of the energy = ?
`=(Pt)/(1 K W *h//"unit")=(300W xx 31 "hours")/(1000 W *h//"unit")`
=9.3 units
Cost =9.3 units `xx` Rs. 3.00 per unit =Rs. 27.9.
The cost of the energy of operate the washing machine for the month of March =Rs. 27.9