Calculate the electricity consumed in a month. If 1 unit cost is Rs. 7.

For the light, 

p_{1= 30 W} 

n₁₌₁₀

t_{1= 5 hrs} 

Electricity consumption in a day  E1 = p_1*n_1*t₁

= 30 *10 * 5 

= 1500 Wh 

=1500/ 1000 Kwh

= 1.5 Kwh 

Now consumption in a month = 30 * 1.5 = 45 unit 

For television p= 40 W, n = 2, t = 4 hrs 

Electricity consumed in a day E2 = p*n*t 

= 40 * 2* 4 

= 320 wh 

= 0.32 Kwh

Now the consumption in a month = 30 * 0.32 = 9.6 

For iron, p = 750, n = 1 , t = 2 * 4 = 8 hrs in a month. 

Electricity consumed in a month E3 = p *n*t 

=750 *1 *8

= 6000 wh 

= 6 kwh

= 6 units 

Similarly for bulb, p = 100 W, n = 4, t = 4 

Electricity consumption in a day (E4) = p*n *t 

= 100 * 4 *4 

= 1600 wh 

= 1.6 kwh

Here , electricty consumed in a month  = 1.6 *30 = 48 units 

Thus, total electricity consumed in a month , E = e1+e2+e3+e4

= 45+9.6+6+8

=108.6 units

Now, total bill = 108.6 *7 

= Rs 760.2

Hence the electricity consumption will be 108.6 units and total bill will be Rs. 760.2.