| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.67 |
| Score | 0% | 73% |
How many hours does it take a car to travel 90 miles at an average speed of 45 miles per hour?
| 8 hours | |
| 1 hour | |
| 2 hours | |
| 6 hours |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for time:
time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{90mi}{45mph} \)
2 hours
A factor is a positive __________ that divides evenly into a given number.
integer |
|
fraction |
|
improper fraction |
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mixed number |
A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 9 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 118.4 | |
| 163.8 | |
| 165.6 | |
| 172.5 |
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 9 = \( \frac{8 \times 9}{100} \) = \( \frac{72}{100} \) = 0.72 errors per hour
So, in an average hour, the machine will produce 9 - 0.72 = 8.28 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 8.28 = 165.6 error free parts were produced yesterday.
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 |
|
a = -7 |
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none of these is correct |
|
a = 7 or a = -7 |
The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).
If a car travels 195 miles in 3 hours, what is the average speed?
| 65 mph | |
| 40 mph | |
| 60 mph | |
| 20 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)