An electric refrigerator rated 400 W is used for 8 hours a day. An electric iron box rated 750 W is used for 2 hours a day. Calculate the cost of using these appliances for 30 days, if the cost of I kWh is Rs 3/-.

An electric refrigerator rated 400 W is used for 8 hours a day. An ele

1.	An electric refrigerator rated 400 W is used for 8 hours a day. An electric iron box rated 750 W is used for 2 hours a day. Calculate the cost of using these appliances for 30 days, if the cost of I kWh is Rs 3/-.
Answer» SOLUTION :The total energy consumed by the refrigerator in 30 days `=400 times 8 times 30=96000 Wh=96kWh` The total energy consumed by the iron BOX in 30 days `=750 times 2 times 30 =45000Wh=45kWh` The total energy consumed by the refrigerator and iron box is `=96kWh+45kWh=141kWh` The sum of bill amount for 141 kWh at rate of Rs. 3 per 1 kWh is `=141 times 3` = Rs. 423