Mini Exam 3 — Timed Mini Exams

Questions in this quiz (10)

1. A guitar string called the G string resonates at 196 Hz. Another string, the B string, resonates at 247 Hz. If the lengths of both strings are reduced to one-third of their original lengths, what is the difference in their new resonant frequencies?

   • $$176\ Hz$$
   • $$204\ Hz$$
   • $$153\ Hz$$
   • $$195\ Hz$$

2. There are 56 numbers in a list. If there are 3 times as many even numbers as there are odd numbers, how many numbers are odd?

   • $$11$$
   • $$14$$
   • $$25$$
   • $$8$$

3. If $$(3x+4)=8$$ and $$(3x+4)m=32,$$ what is the value of $$m$$?

   • 4
   • 6
   • 8
   • 10

4. $$2x+5y=11$$$$5x+2y=4$$What is the value of $$x+y$$ in the system of equations shown above?

   • $$3$$
   • $$2$$
   • $$1$$
   • $$\frac{15}{7}$$

5. $$f(x)=3x^2+b$$If $$b$$ is a constant and $$f(1)+f(4)=f(5),$$ what is the value of $$b$$?

   • 9
   • 15
   • 18
   • 24

6. If $$\sqrt{6x+27}=x+3,$$ what is the value of $$x$$ divided by two?

   • $$-\frac{3\sqrt{2}}{2}$$
   • $$\frac{3\sqrt{2}}{2}$$
   • $$\pm\frac{3\sqrt{2}}{2}$$
   • $$0$$

7. If $$4x^2-4y^2=168$$ and $$x+y=14,$$ what is the value of $$x-y$$?

   • 2
   • 3
   • 8
   • 0

8. A dolphin spends 25% of a day, $$d,$$ playing and 50% of the remaining time hunting. Which of the following expressions represents how many hours in one day are left for other activities?

   • $$\frac{3d}{8}$$
   • $$\frac{d}{4}$$
   • $$\frac{3d}{4}$$
   • $$\frac{d}{8}$$

9. The average in Set A is 90 and the average in Set B is 60. If the combined average of all the elements in Set A and Set B is 75, and Set A has 8 elements, how many elements are in Set B?

   • 8
   • 12
   • 16
   • 20

10. Which of the following could be the sum of 3 consecutive even integers?

    • 45
    • 53
    • 81
    • 42