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

We know that

1 unit = 3,600,000 J

So,

250 units = 250 × 3,600,000 J

= 900,000,000 J

= 9 × 10⁸ J

Hence, the energy consumed = 9 × 10⁸ J