Calculating Fair Share from a Monthly Electricity Bill: A Practical Example

Calculating Fair Share from a Monthly Electricity Bill: A Practical Example

Dividing the cost of a monthly electricity bill among a family living in a household is a common task. This article explores a real-life scenario involving an 8-person family and provides a detailed step-by-step approach to distribute the bill fairly based on usage days.

The total monthly electricity bill for this family is 3110. The family consists of 8 members, with different individuals using the electricity for varying durations. Here's how we can determine their fair share:

The Scenario

Three members use the electricity for 31 days, while the next three members use it for 24 days. The fourth member uses it for 18 days, and the fifth member uses it for 5 days. These durations are converted into member-days to determine the share of the bill.

Step-by-Step Calculation

First, let's convert the days to a common unit by calculating the total member-days:

3 members * 31 days 93 member-days 3 members * 24 days 72 member-days 1 member * 18 days 18 member-days 1 member * 5 days 5 member-days

The total member-days is the sum of these values:

Total member-days 93 72 18 5 188 member-days

Determining the Cost per Member-Day

The cost per member-day can be calculated as follows:

Cost per member-day Total Bill / Total member-days

Cost per member-day 3110 / 188 16.542

Calculating Each Group's Share

Now, using the cost per member-day, we can determine the share of the bill for each group:

1st Group

3 members * 31 days 93 member-days

Share for the 1st group 93 * 16.542 1538.40

Dividing the total share by 3 (members in the group) gives:

Share per person 1538.40 / 3 512.80

2nd Group

3 members * 24 days 72 member-days

Share for the 2nd group 72 * 16.542 1190.88

Dividing the total share by 3 (members in the group) gives:

Share per person 1190.88 / 3 396.96

3rd Group

1 member * 18 days 18 member-days

Share 18 * 16.542 297.76

4th Group

1 member * 5 days 5 member-days

Share 5 * 16.542 82.7

Conclusion

By following these straightforward steps, one can effectively distribute the cost of the monthly electricity bill among all household members based on their usage. This ensures fairness and transparency within the household.