| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.07 |
| Score | 0% | 61% |
\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
commutative property for multiplication |
|
commutative property for division |
|
distributive property for multiplication |
|
distributive 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 machine in a factory has an error rate of 2 parts per 100. The machine normally runs 24 hours a day and produces 5 parts per hour. Yesterday the machine was shut down for 7 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 96.6 | |
| 141.7 | |
| 83.3 | |
| 154.7 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{2}{100} \) x 5 = \( \frac{2 \times 5}{100} \) = \( \frac{10}{100} \) = 0.1 errors per hour
So, in an average hour, the machine will produce 5 - 0.1 = 4.9 error free parts.
The machine ran for 24 - 7 = 17 hours yesterday so you would expect that 17 x 4.9 = 83.3 error free parts were produced yesterday.
If a car travels 560 miles in 8 hours, what is the average speed?
| 20 mph | |
| 70 mph | |
| 45 mph | |
| 50 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)If a mayor is elected with 69% of the votes cast and 79% of a town's 26,000 voters cast a vote, how many votes did the mayor receive?
| 15,816 | |
| 14,173 | |
| 16,843 | |
| 14,583 |
If 79% of the town's 26,000 voters cast ballots the number of votes cast is:
(\( \frac{79}{100} \)) x 26,000 = \( \frac{2,054,000}{100} \) = 20,540
The mayor got 69% of the votes cast which is:
(\( \frac{69}{100} \)) x 20,540 = \( \frac{1,417,260}{100} \) = 14,173 votes.
What is 8y6 + 9y6?
| -y6 | |
| y-6 | |
| 17y6 | |
| y6 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:
8y6 + 9y6
(8 + 9)y6
17y6