| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.14 |
| Score | 0% | 63% |
How many hours does it take a car to travel 540 miles at an average speed of 60 miles per hour?
| 2 hours | |
| 9 hours | |
| 8 hours | |
| 7 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 = \( \frac{540mi}{60mph} \)
9 hours
If a mayor is elected with 85% of the votes cast and 77% of a town's 48,000 voters cast a vote, how many votes did the mayor receive?
| 21,437 | |
| 33,264 | |
| 31,416 | |
| 19,958 |
If 77% of the town's 48,000 voters cast ballots the number of votes cast is:
(\( \frac{77}{100} \)) x 48,000 = \( \frac{3,696,000}{100} \) = 36,960
The mayor got 85% of the votes cast which is:
(\( \frac{85}{100} \)) x 36,960 = \( \frac{3,141,600}{100} \) = 31,416 votes.
The __________ is the greatest factor that divides two integers.
least common multiple |
|
greatest common factor |
|
absolute value |
|
greatest common multiple |
The greatest common factor (GCF) is the greatest factor that divides two integers.
Convert 0.0006488 to scientific notation.
| 0.649 x 10-3 | |
| 6.488 x 104 | |
| 64.88 x 10-5 | |
| 6.488 x 10-4 |
A number in scientific notation has the format 0.000 x 10exponent. To convert to scientific notation, move the decimal point to the right or the left until the number is a decimal between 1 and 10. The exponent of the 10 is the number of places you moved the decimal point and is positive if you moved the decimal point to the left and negative if you moved it to the right:
0.0006488 in scientific notation is 6.488 x 10-4
A machine in a factory has an error rate of 2 parts per 100. The machine normally runs 24 hours a day and produces 9 parts per hour. Yesterday the machine was shut down for 5 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 161.3 | |
| 182.2 | |
| 73.6 | |
| 167.6 |
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 9 = \( \frac{2 \times 9}{100} \) = \( \frac{18}{100} \) = 0.18 errors per hour
So, in an average hour, the machine will produce 9 - 0.18 = 8.82 error free parts.
The machine ran for 24 - 5 = 19 hours yesterday so you would expect that 19 x 8.82 = 167.6 error free parts were produced yesterday.