A financial services consulting company bought an office building for $900,000. The company has 10 professional staff members. Monthly expenses for salaries, utilities, grounds maintenance, etc. are $1.1 million. The average billing rate per professional is $90 per hour. Use an interest rate of 1% per month and assume the building will have a resale value of $1.5 million after 10 years.

(a) How many hours per month must be billed in order to make a profit of $15,000 per month?

(b) How many hours per professional per month must be billed?

(c) There are 260 eight-hour workdays per year. Of the total work hours available per month, what percentage does the hours per professional in part (b) represent?