The Ivanhoe Aces Inn is trying to determine its break-even point during the off-peak season. The inn has 50 rooms that it rents at $55 a night. Operating costs are as follows: salaries $5,700 per month, property tax $1,000 per month, depreciation (straight-line) $1,300 per month, maintenance $250 per month, maid service $11 per room, other cost $22 per room. Determine the inn's break-even point in the number of rented rooms per month.
a) 90 rooms
b) 100 rooms
c) 110 rooms
d) 120 rooms