| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.03 |
| Score | 0% | 61% |
\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
commutative property for multiplication |
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distributive property for multiplication |
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distributive property for division |
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commutative property for division |
The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).
What is \( \frac{3}{6} \) ÷ \( \frac{1}{5} \)?
| 2\(\frac{1}{2}\) | |
| \(\frac{16}{45}\) | |
| \(\frac{1}{10}\) | |
| \(\frac{12}{25}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{3}{6} \) ÷ \( \frac{1}{5} \) = \( \frac{3}{6} \) x \( \frac{5}{1} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{3}{6} \) x \( \frac{5}{1} \) = \( \frac{3 x 5}{6 x 1} \) = \( \frac{15}{6} \) = 2\(\frac{1}{2}\)
A machine in a factory has an error rate of 9 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 3 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 186 | |
| 92 | |
| 152.9 | |
| 148.8 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{9}{100} \) x 8 = \( \frac{9 \times 8}{100} \) = \( \frac{72}{100} \) = 0.72 errors per hour
So, in an average hour, the machine will produce 8 - 0.72 = 7.28 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 7.28 = 152.9 error free parts were produced yesterday.
What is the greatest common factor of 16 and 76?
| 9 | |
| 7 | |
| 4 | |
| 8 |
The factors of 16 are [1, 2, 4, 8, 16] and the factors of 76 are [1, 2, 4, 19, 38, 76]. They share 3 factors [1, 2, 4] making 4 the greatest factor 16 and 76 have in common.
If a mayor is elected with 63% of the votes cast and 65% of a town's 25,000 voters cast a vote, how many votes did the mayor receive?
| 10,238 | |
| 12,188 | |
| 13,650 | |
| 9,425 |
If 65% of the town's 25,000 voters cast ballots the number of votes cast is:
(\( \frac{65}{100} \)) x 25,000 = \( \frac{1,625,000}{100} \) = 16,250
The mayor got 63% of the votes cast which is:
(\( \frac{63}{100} \)) x 16,250 = \( \frac{1,023,750}{100} \) = 10,238 votes.