| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.06 |
| Score | 0% | 61% |
If \( \left|a + 3\right| \) - 3 = 2, which of these is a possible value for a?
| -8 | |
| 8 | |
| 11 | |
| 15 |
First, solve for \( \left|a + 3\right| \):
\( \left|a + 3\right| \) - 3 = 2
\( \left|a + 3\right| \) = 2 + 3
\( \left|a + 3\right| \) = 5
The value inside the absolute value brackets can be either positive or negative so (a + 3) must equal + 5 or -5 for \( \left|a + 3\right| \) to equal 5:
| a + 3 = 5 a = 5 - 3 a = 2 | a + 3 = -5 a = -5 - 3 a = -8 |
So, a = -8 or a = 2.
Find the average of the following numbers: 8, 4, 7, 5.
| 9 | |
| 1 | |
| 6 | |
| 3 |
To find the average of these 4 numbers add them together then divide by 4:
\( \frac{8 + 4 + 7 + 5}{4} \) = \( \frac{24}{4} \) = 6
| 0.6 | |
| 1 | |
| 0.8 | |
| 0.2 |
1
Christine scored 93% on her final exam. If each question was worth 4 points and there were 360 possible points on the exam, how many questions did Christine answer correctly?
| 84 | |
| 91 | |
| 92 | |
| 77 |
Christine scored 93% on the test meaning she earned 93% of the possible points on the test. There were 360 possible points on the test so she earned 360 x 0.93 = 336 points. Each question is worth 4 points so she got \( \frac{336}{4} \) = 84 questions right.
What is \( \frac{4}{2} \) + \( \frac{8}{4} \)?
| 2 \( \frac{3}{9} \) | |
| \( \frac{2}{11} \) | |
| 4 | |
| 1 \( \frac{2}{4} \) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 2 are [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] and the first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40]. The first few multiples they share are [4, 8, 12, 16, 20] making 4 the smallest multiple 2 and 4 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{4 x 2}{2 x 2} \) + \( \frac{8 x 1}{4 x 1} \)
\( \frac{8}{4} \) + \( \frac{8}{4} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{8 + 8}{4} \) = \( \frac{16}{4} \) = 4