Question

Please someone please can you help

Answer 1

Answer:518.4

Step-by-step explanation:

Let the power of bulb used be
`P` watts.

In
`1` second,
`P` joules of energy is consumed.

In
`1` minute,
`P* 60=60P` joules of energy is consumed.

In
`1` hour,
`60P* 60=3600P` joules of energy is consumed.

In
`1` day,
`3600P* 24=86400P` joules of energy is consumed.

In
`1` month,
`30* 86400P=2592000P` joules of energy.

As we know that
`1KWh=3600000joules`

So,required energy in
`KWh` is
`(2592000P)/(3600000)=0.72PKWh`

Given that the power of the bulb used is
`100` watts.

So,required energy is
`0.72* 100=72KWh`

Given that cost of one
`KWh` is
`7.2`

So,cost of
`72KWh` is
`72* 7.2=518.4`