| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
If \(\left|a\right| = 7\), which of the following best describes a?
none of these is correct |
|
a = 7 |
|
a = -7 |
|
a = 7 or a = -7 |
The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).
If \( \left|a - 3\right| \) + 3 = -9, which of these is a possible value for a?
| -1 | |
| -9 | |
| 3 | |
| 5 |
First, solve for \( \left|a - 3\right| \):
\( \left|a - 3\right| \) + 3 = -9
\( \left|a - 3\right| \) = -9 - 3
\( \left|a - 3\right| \) = -12
The value inside the absolute value brackets can be either positive or negative so (a - 3) must equal - 12 or --12 for \( \left|a - 3\right| \) to equal -12:
| a - 3 = -12 a = -12 + 3 a = -9 | a - 3 = 12 a = 12 + 3 a = 15 |
So, a = 15 or a = -9.
Monica scored 82% on her final exam. If each question was worth 2 points and there were 100 possible points on the exam, how many questions did Monica answer correctly?
| 56 | |
| 30 | |
| 41 | |
| 27 |
Monica scored 82% on the test meaning she earned 82% of the possible points on the test. There were 100 possible points on the test so she earned 100 x 0.82 = 82 points. Each question is worth 2 points so she got \( \frac{82}{2} \) = 41 questions right.
How many hours does it take a car to travel 520 miles at an average speed of 65 miles per hour?
| 7 hours | |
| 2 hours | |
| 6 hours | |
| 8 hours |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for time:
time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{520mi}{65mph} \)
8 hours
Charlie loaned Christine $800 at an annual interest rate of 6%. If no payments are made, what is the total amount owed at the end of the first year?
| $840 | |
| $848 | |
| $832 | |
| $816 |
The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:
interest = annual interest rate x loan amount
i = (\( \frac{6}{100} \)) x $800
i = 0.06 x $800
No payments were made so the total amount due is the original amount + the accumulated interest:
total = $800 + $48