tolong bantuannya ......

20x4=80 watt
80x2=160 watt
60x1=60 watt

80+160+60=300 watt
300watt:1000=0,3kw
0,3 x 3jam=0,9 kwh x 30 hari x Rp 600

=27 x 600 = Rp 16.200