## Math For Social Sciences. Practice Exam

1. Use the elimination method to solve each of the following systems:
• Answer: x=-z, y=-1+2z, z=z.

• Answer: x=3 and y=4.

2. Let , , and .
• Give the dimensions of each matrix, and identify any square, column, or row matrices.

Answer: A is a matrix. B is a column matrix. C is a row matrix. D is a square matrix.

• Find the following if possible:

Answer: • BC.

Answer: • CA.

Answer: 3. Use the Gauss Jordan method to solve the following system: Answer: x=-1, y=1, and z=-2.

4. Use the method of matrix inverses to solve the following system: Answer: x=1 and y=-1.

5. A 45-year-old man puts \$1,000 in a retirement account at the beginning of each quarter until he reaches the age of 60 and makes no further deposits. If the account pays 11% interest compounded quarterly, how much will be in the account when the man reaches age 60?

Answer: The money in the account will be approximately \$148,809.

6. A speculator agrees to pay \$15,999 for a parcel of land; this amount, with interest, will be paid over 4 yr, with semiannual payments, at an interest rate of 10% compounded semiannually. Find the amount of each payment.

Answer: Each payment will be approximately \$2475.39.

Formulas

• Future value for simple interest: • Future value for compound interest: • Future value of an ordinary annuity: • Future value of an annuity due: • Present value of an annuity: • Amortizing a loan: If you would like to practice on the comprehensive final, click on Final.

If you would like to practice on other exams, click on Menu. It will take you back to the original Menu.

Tue Aug 12 21:51:10 MDT 1997