| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.11 |
| Score | 0% | 62% |
Which of these numbers is a factor of 48?
| 2 | |
| 49 | |
| 14 | |
| 13 |
The factors of a number are all positive integers that divide evenly into the number. The factors of 48 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 48.
A bread recipe calls for 2\(\frac{3}{8}\) cups of flour. If you only have \(\frac{5}{8}\) cup, how much more flour is needed?
| 2\(\frac{3}{8}\) cups | |
| \(\frac{3}{8}\) cups | |
| 1\(\frac{3}{4}\) cups | |
| 1\(\frac{1}{8}\) cups |
The amount of flour you need is (2\(\frac{3}{8}\) - \(\frac{5}{8}\)) cups. Rewrite the quantities so they share a common denominator and subtract:
(\( \frac{19}{8} \) - \( \frac{5}{8} \)) cups
\( \frac{14}{8} \) cups
1\(\frac{3}{4}\) cups
A machine in a factory has an error rate of 4 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 121 | |
| 153.6 | |
| 192 | |
| 131 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{4}{100} \) x 10 = \( \frac{4 \times 10}{100} \) = \( \frac{40}{100} \) = 0.4 errors per hour
So, in an average hour, the machine will produce 10 - 0.4 = 9.6 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 9.6 = 192 error free parts were produced yesterday.
What is \( \frac{2}{6} \) + \( \frac{3}{12} \)?
| \(\frac{7}{12}\) | |
| 1 \( \frac{1}{8} \) | |
| \( \frac{6}{14} \) | |
| 1 \( \frac{9}{12} \) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [12, 24, 36, 48, 60] making 12 the smallest multiple 6 and 12 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{2 x 2}{6 x 2} \) + \( \frac{3 x 1}{12 x 1} \)
\( \frac{4}{12} \) + \( \frac{3}{12} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{4 + 3}{12} \) = \( \frac{7}{12} \) = \(\frac{7}{12}\)
What is \( \sqrt{\frac{81}{49}} \)?
| 3 | |
| 1\(\frac{2}{7}\) | |
| 1\(\frac{1}{3}\) | |
| \(\frac{2}{3}\) |
To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:
\( \sqrt{\frac{81}{49}} \)
\( \frac{\sqrt{81}}{\sqrt{49}} \)
\( \frac{\sqrt{9^2}}{\sqrt{7^2}} \)
\( \frac{9}{7} \)
1\(\frac{2}{7}\)