| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
What is \( \frac{3}{8} \) x \( \frac{2}{9} \)?
| \(\frac{1}{18}\) | |
| \(\frac{2}{3}\) | |
| \(\frac{3}{4}\) | |
| \(\frac{1}{12}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{3}{8} \) x \( \frac{2}{9} \) = \( \frac{3 x 2}{8 x 9} \) = \( \frac{6}{72} \) = \(\frac{1}{12}\)
What is 9\( \sqrt{6} \) x 8\( \sqrt{6} \)?
| 72\( \sqrt{6} \) | |
| 17\( \sqrt{36} \) | |
| 72\( \sqrt{12} \) | |
| 432 |
To multiply terms with radicals, multiply the coefficients and radicands separately:
9\( \sqrt{6} \) x 8\( \sqrt{6} \)
(9 x 8)\( \sqrt{6 \times 6} \)
72\( \sqrt{36} \)
Now we need to simplify the radical:
72\( \sqrt{36} \)
72\( \sqrt{6^2} \)
(72)(6)
432
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 5 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 147.2 | |
| 146.3 | |
| 101.2 | |
| 123.5 |
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 5 = \( \frac{8 \times 5}{100} \) = \( \frac{40}{100} \) = 0.4 errors per hour
So, in an average hour, the machine will produce 5 - 0.4 = 4.6 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 4.6 = 101.2 error free parts were produced yesterday.
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
|
none of these is correct |
|
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).
Convert z-5 to remove the negative exponent.
| \( \frac{-1}{-5z} \) | |
| \( \frac{1}{z^5} \) | |
| \( \frac{-5}{z} \) | |
| \( \frac{-5}{-z} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.