Question

A $60W$ bulb is used $10hrs$ per day. If the cost of electricity is 4 rs per unit, then the bill for the month of February in a leap year is_____

• A. 240 rs
• B. 70 rs
• C. 120 rs
• D. 75 rs

Answer 1

The correct option is B

70 rs

Step 1: Analyse the situation and given data

We are given the power of bulb $60\hspace{0.17em}W=0.06kW$

It is used for $10hrs$ per day in the February leap year.

So, in the February leap year, the total usage time for 29 days is $10\times 290=290hrs$

Step 3: Calculate the total energy

We know that $Energy=Power\times time.$

So, the total energy consumed by in $kWhr$ of the bulb in February month will be

$0.06kW\times 290hrs=17.4kWhr$

Step 3: Calculate the price

Given one unit electricity = $1kWhr$. Price of one unit electricity is given 3 Rs.

So, the price of $17.4kWhr$ will be $17.4\times 4=69.6Rs\approx 70Rs$

So, the correct option will be (B)70 Rs.