Final answer:
To find the greatest number of people they may invite and still stay within their budget, set up an equation and solve for the number of people. The answer is 81.
Step-by-step explanation:
To find the greatest number of people they may invite and still stay within their budget, we need to set up an equation based on the given information. Let 'x' represent the number of people they invite. The total cost will be the cleanup fee plus the cost per person multiplied by the number of people:
Total Cost = Cleanup Fee + (Cost per Person * Number of People)
Plugging in the values:
Total Cost = $70 + ($30 * x)
Since they have budgeted $2,500, the equation becomes:
$2,500 = $70 + ($30 * x)
Now, we can solve for 'x', the number of people:
$2,500 - $70 = $30x
$2,430 = $30x
x = 81
Therefore, the greatest number of people they may invite and still stay within their budget is 81. However, none of the given options match with this number, so there may be a mistake in the options.