| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.58 |
| Score | 0% | 72% |
Which of the following is not an integer?
\({1 \over 2}\) |
|
0 |
|
-1 |
|
1 |
An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.
How many hours does it take a car to travel 150 miles at an average speed of 75 miles per hour?
| 2 hours | |
| 8 hours | |
| 9 hours | |
| 5 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 = \( \frac{150mi}{75mph} \)
2 hours
A machine in a factory has an error rate of 6 parts per 100. The machine normally runs 24 hours a day and produces 6 parts per hour. Yesterday the machine was shut down for 6 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 156.8 | |
| 78.2 | |
| 101.5 | |
| 141.1 |
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 6 = \( \frac{6 \times 6}{100} \) = \( \frac{36}{100} \) = 0.36 errors per hour
So, in an average hour, the machine will produce 6 - 0.36 = 5.64 error free parts.
The machine ran for 24 - 6 = 18 hours yesterday so you would expect that 18 x 5.64 = 101.5 error free parts were produced yesterday.
The total water usage for a city is 15,000 gallons each day. Of that total, 25% is for personal use and 39% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 11,900 | |
| 6,200 | |
| 8,400 | |
| 2,100 |
39% of the water consumption is industrial use and 25% is personal use so (39% - 25%) = 14% more water is used for industrial purposes. 15,000 gallons are consumed daily so industry consumes \( \frac{14}{100} \) x 15,000 gallons = 2,100 gallons.
4! = ?
3 x 2 x 1 |
|
5 x 4 x 3 x 2 x 1 |
|
4 x 3 |
|
4 x 3 x 2 x 1 |
A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.