The room is lit by five light bulbs connected in series, the number of light bulbs has

The room is lit by five light bulbs connected in series, the number of light bulbs has been reduced by 1, how then will the electricity consumption change?

Determine the currents I1 and I2 through 5 bulbs and through 4 bulbs
I1 = E / 5R;
I2 = E / 4R.
The power allocated to the bulbs:
P1 = E * I1 = E * (E / 5R);
P2 = E * I2 = E * (E / 4R);

Let’s find the power ratio:
P2 / P1 = E * (E / 4R) / E * (E / 5R) = 5R / 4R = 5/4 = 1.25.

Answer: The power consumption will increase by 1.25 times.