1. Find the present value of an ordinary annuity with annual payments of $1,000, for 6 years, at 10% interest compounded annually.
2. In a marketing survey, consumers are asked to give their first three choices, of 9 different drinks. In how many different ways can they indicate their choices?
3. A class consists of 15 students. The instructor wants to pick a group of 4 to work on a special project.
a. How many different groups of 4 can he choose?
b. If the class consists of 10 girls and 5 boys, how many different groups of 4 are made up of 2 boys and 2 girls?
4. How many license plates can a state have if each license plate has 2 letters followed by 4 digits, if the first digit cannot be zero?
The first part of the solution explains in detail on how to calculate the present value of an ordinary annuity. The second part of the solution elaborates on the combination and permutaion problems.