How many different ways can 13 questions on true-false test be answered if a student answers every question?

The vet charges $45 for an office visit and $10 for each vaccination your dog needs. write an eaquation

12 out of 30 people chose their favourite colour as blue caculate the angle you would use for blue on a pie chart

You borrow $25,000 to buy a boat. the simple interest rate is 4%. you pay the loan off after 10 years. what is the total amount you paid for the loan?