| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.14 |
| Score | 0% | 63% |
This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
commutative |
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distributive |
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PEDMAS |
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associative |
The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.
A machine in a factory has an error rate of 7 parts per 100. The machine normally runs 24 hours a day and produces 7 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 135.4 | |
| 160.7 | |
| 143.2 | |
| 86.4 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 7 = \( \frac{7 \times 7}{100} \) = \( \frac{49}{100} \) = 0.49 errors per hour
So, in an average hour, the machine will produce 7 - 0.49 = 6.51 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 6.51 = 143.2 error free parts were produced yesterday.
Damon loaned Damon $200 at an annual interest rate of 8%. If no payments are made, what is the interest owed on this loan at the end of the first year?
| $16 | |
| $28 | |
| $5 | |
| $44 |
The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:
interest = annual interest rate x loan amount
i = (\( \frac{6}{100} \)) x $200
i = 0.08 x $200
i = $16
What is \( \frac{4}{5} \) x \( \frac{3}{9} \)?
| \(\frac{1}{6}\) | |
| 1\(\frac{1}{3}\) | |
| \(\frac{4}{15}\) | |
| \(\frac{1}{5}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{4}{5} \) x \( \frac{3}{9} \) = \( \frac{4 x 3}{5 x 9} \) = \( \frac{12}{45} \) = \(\frac{4}{15}\)
The total water usage for a city is 15,000 gallons each day. Of that total, 14% is for personal use and 48% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 5,100 | |
| 8,500 | |
| 1,100 | |
| 1,500 |
48% of the water consumption is industrial use and 14% is personal use so (48% - 14%) = 34% more water is used for industrial purposes. 15,000 gallons are consumed daily so industry consumes \( \frac{34}{100} \) x 15,000 gallons = 5,100 gallons.