30. Robert has $50 to spend on his utility bills each month. The basic monthly charge for water and sewer is $23.77. Electricity costs $0.1116 for each kilowatt hour used. The inequality 0.1116x + 23.77 ? 50 represents Robert's monthly utility budget. To the nearest kilowatt hour, what is the maximum number of kilowatt hours of electricity that Robert can Use without going over his monthly budget amount?
Answer: B
Robert can use a maximum of 235 kilowatt hours of electricity without exceeding his monthly budget.
To determine how many kilowatt hours of electricity Robert can use, we solve the inequality \(0.1116x + 23.77 \leq 50\). This calculation reveals that the maximum kilowatt hours he can afford is 235.
A) 661
This option significantly exceeds Robert's budget. If he were to use 661 kilowatt hours, the equation would result in a total charge far greater than $50, making it an impossible choice within his financial constraints.
B) 235
This is the correct answer. Solving the inequality gives \(x \leq \frac{50 - 23.77}{0.1116} \approx 235\). Therefore, Robert can use up to 235 kilowatt hours of electricity without exceeding his budget.
C) 448
Choosing 448 kilowatt hours would also surpass Robert's budget. The calculations show that this option would lead to a total expenditure well over $50, thus it cannot be the correct answer.
D) 424
Similar to option C, using 424 kilowatt hours would result in a total utility cost that exceeds Robert's budget. The calculations confirm that this choice is not feasible given his financial limit.
Conclusion
In conclusion, the maximum number of kilowatt hours Robert can use without exceeding his monthly budget is definitively 235. All other options either exceed his budget or are not feasible based on the calculations derived from the given inequality.