| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
How many 1\(\frac{1}{2}\) gallon cans worth of fuel would you need to pour into an empty 6 gallon tank to fill it exactly halfway?
| 3 | |
| 8 | |
| 4 | |
| 2 |
To fill a 6 gallon tank exactly halfway you'll need 3 gallons of fuel. Each fuel can holds 1\(\frac{1}{2}\) gallons so:
cans = \( \frac{3 \text{ gallons}}{1\frac{1}{2} \text{ gallons}} \) = 2
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
|
a = 7 or a = -7 |
|
a = 7 |
|
none of these is correct |
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 70 miles in 2 hours, what is the average speed?
| 35 mph | |
| 75 mph | |
| 25 mph | |
| 65 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)The __________ is the greatest factor that divides two integers.
greatest common multiple |
|
least common multiple |
|
absolute value |
|
greatest common factor |
The greatest common factor (GCF) is the greatest factor that divides two integers.
A machine in a factory has an error rate of 6 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 6 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 81.9 | |
| 169.2 | |
| 139.7 | |
| 152 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{6}{100} \) x 10 = \( \frac{6 \times 10}{100} \) = \( \frac{60}{100} \) = 0.6 errors per hour
So, in an average hour, the machine will produce 10 - 0.6 = 9.4 error free parts.
The machine ran for 24 - 6 = 18 hours yesterday so you would expect that 18 x 9.4 = 169.2 error free parts were produced yesterday.