Question

A 620w refrigerator operates for 12hour per day. Calculate the cost to operate it for 31 days at the cost of rs.4.5 per unit

Answer 1

$total \: cost \: of \: unit \: in \: whole \: month \: = 620 \times 12 \times 31 = 230640 = 230.64bot \\ thereafter \: monthly \: cost = 230.6 \times 4.5 = rs1037.7$