| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.08 |
| Score | 0% | 62% |
What is \( \frac{1}{9} \) x \( \frac{3}{6} \)?
| \(\frac{1}{3}\) | |
| \(\frac{1}{18}\) | |
| \(\frac{2}{5}\) | |
| \(\frac{1}{2}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{1}{9} \) x \( \frac{3}{6} \) = \( \frac{1 x 3}{9 x 6} \) = \( \frac{3}{54} \) = \(\frac{1}{18}\)
What is \( \frac{6}{8} \) + \( \frac{9}{12} \)?
| \( \frac{5}{9} \) | |
| \( \frac{1}{10} \) | |
| 1 \( \frac{9}{13} \) | |
| 1\(\frac{1}{2}\) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80] and the first few multiples of 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [24, 48, 72, 96] making 24 the smallest multiple 8 and 12 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{6 x 3}{8 x 3} \) + \( \frac{9 x 2}{12 x 2} \)
\( \frac{18}{24} \) + \( \frac{18}{24} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{18 + 18}{24} \) = \( \frac{36}{24} \) = 1\(\frac{1}{2}\)
\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
distributive property for division |
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commutative property for multiplication |
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distributive property for multiplication |
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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, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 45% off." If Frank buys two shirts, each with a regular price of $14, how much money will he save?
| $0.70 | |
| $6.30 | |
| $4.90 | |
| 61 |
By buying two shirts, Frank will save $14 x \( \frac{45}{100} \) = \( \frac{$14 x 45}{100} \) = \( \frac{$630}{100} \) = $6.30 on the second shirt.
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 139.7 | |
| 82.8 | |
| 154.7 | |
| 202.4 |
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 10 = \( \frac{8 \times 10}{100} \) = \( \frac{80}{100} \) = 0.8 errors per hour
So, in an average hour, the machine will produce 10 - 0.8 = 9.2 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 9.2 = 202.4 error free parts were produced yesterday.