A certain household has consumed 250 units of energy during a month. How much energy is this in joules?

• 1 unit of energy is equal to a 1-kilowatt hour (kWh).
• Energy (E) = 250 units

1 unit = 1 kWh

1 kWh = 3.6 x 106 J

Therefore,

Energy = 250 x 3.6 x 106 J

E = 900 x 106 J

E = 9 x 108 J

Thus, the household consumes 9 x 108 J or 900 MJ of energy in a month.