Question Number 6495 by sanusihammed last updated on 29/Jun/16
$${A}\:{refrigerator}\:{is}\:{rated}\:\mathrm{20}\:{watts}\:{of}\:{electricity}\:{which} \\ $$$${cost}\:\mathrm{5}{k}\:{per}\:{kwh}\:,\:{what}\:{is}\:{the}\:{cost}\:{of}\:{operation}\:{for}\:\mathrm{20}\:{days}. \\ $$
Answered by sandy_suhendra last updated on 30/Jun/16
$$\mathrm{20}\:{days}×\mathrm{24}\:{hour}×\mathrm{20}\:{watts}=\mathrm{9600}\:{wh}=\mathrm{9}.\mathrm{6}{kwh} \\ $$$${it}'{s}\:{cost}=\mathrm{9}.\mathrm{6}×\mathrm{5}{k}=\mathrm{48}{k} \\ $$