# Math 160: Study Guide - Chapters 3&4

1. Identify which type of problem (simple interest, compound interest, future value annuity, or present value annuity) is applicable. Do not attempt to answer the question, only identify the type of problem you would need to answer the question. Five parts.
2. Financial problem. I'm being purposely vague here. It could be any of the compound interest, future value, or present value problems.
3. Financial problem
4. Financial problem
5. Retirement problem: Find the present value needed to retire, then find the payment needed under a future value to reach that goal.
6. Home loan: Find the monthly payment and the total interest paid.
7. Home loan: The details of a loan are given. Find the remaining balance after a fixed time and the equity in the house at that point.
8. Home loan: The details of a loan are given. Find the time to pay off the loan if extra is paid and the amount of money saved by paying extra.
9. Solve the equation for X. Three parts. Know how to handle factoring of matrices and scalar multiplication. Look at problems 4.6.37-42 and the project for chapter 4.
10. Write the solution to the system of linear equations from the augmented matrix. Four parts ... including the special cases. The matrices may be in either row echelon form or reduced row echelon form. Look at problems 4.3.11-20.
11. Perform the row operations on the matrix. Three parts. Look at problems 4.2.13-24.
12. One row operation has been performed to a matrix. Determine what that row operation is. Two parts. Look at problems 4.2.25-34.
13. Multiply the matrices by hand and simplify the result. Look at problems 4.4.11-14 and 55-58, but practice on larger matrices.
14. Leontief Input-Output Analysis. Write the input-output matrix and find the output. Look at problems 4.7.27-34.

## Notes

• The test is individual, there are no groups allowed on this in-class portion.
• There is a take home portion of the test that is due at the beginning of the test on the day of the exam.
• There are five questions worth 5 points each for a total of 25 points.
• Your scores will be higher if you work together (unless you get in with the wrong group).
• You will need the results of the Northwestern NAQT scholastic bowl tournament from November 1, 2008, to answer one of the questions.
• Show work!
• You will need your calculator for the test. The test is designed so that much of the work is performed on the calculator. If you sit there and do it by hand, you're going to have trouble getting through the test in the given time.
• Show enough work so that I can give partial credit if you're wrong. That may mean just writing down what you're looking for and what you entered into the calculator for some problems, but if there's nothing but an answer, you better make sure it's right.
• Have you act together when you come in to take the test. Know your material. Go through and work the easiest problems first, not necessarily the order they're given to you on the test.

## Points per problem

 # Pts 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Take Home Total 5 3 6 3 9 6 6 6 6 8 6 4 3 4 25 100