| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.48 |
| Score | 0% | 70% |
Simplify \( \frac{28}{44} \).
| \( \frac{1}{2} \) | |
| \( \frac{3}{5} \) | |
| \( \frac{7}{11} \) | |
| \( \frac{2}{3} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 28 are [1, 2, 4, 7, 14, 28] and the factors of 44 are [1, 2, 4, 11, 22, 44]. They share 3 factors [1, 2, 4] making 4 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{28}{44} \) = \( \frac{\frac{28}{4}}{\frac{44}{4}} \) = \( \frac{7}{11} \)
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 or a = -7 |
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a = 7 |
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none of these is correct |
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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).
What is the least common multiple of 2 and 4?
| 3 | |
| 6 | |
| 4 | |
| 8 |
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 have in common.
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 7 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 192.1 | |
| 150.7 | |
| 150.4 | |
| 128.8 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{8}{100} \) x 7 = \( \frac{8 \times 7}{100} \) = \( \frac{56}{100} \) = 0.56 errors per hour
So, in an average hour, the machine will produce 7 - 0.56 = 6.4399999999999995 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 6.4399999999999995 = 128.8 error free parts were produced yesterday.
A factor is a positive __________ that divides evenly into a given number.
improper fraction |
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mixed number |
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integer |
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fraction |
A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.