| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.02 |
| Score | 0% | 60% |
Which of the following is not a prime number?
7 |
|
5 |
|
9 |
|
2 |
A prime number is an integer greater than 1 that has no factors other than 1 and itself. Examples of prime numbers include 2, 3, 5, 7, and 11.
The __________ is the smallest positive integer that is a multiple of two or more integers.
greatest common factor |
|
least common multiple |
|
least common factor |
|
absolute value |
The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.
A machine in a factory has an error rate of 4 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 88.4 | |
| 134.4 | |
| 126.7 | |
| 153.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{4}{100} \) x 8 = \( \frac{4 \times 8}{100} \) = \( \frac{32}{100} \) = 0.32 errors per hour
So, in an average hour, the machine will produce 8 - 0.32 = 7.68 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 7.68 = 153.6 error free parts were produced yesterday.
The total water usage for a city is 50,000 gallons each day. Of that total, 12% is for personal use and 26% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 7,000 | |
| 4,500 | |
| 4,000 | |
| 14,499 |
26% of the water consumption is industrial use and 12% is personal use so (26% - 12%) = 14% more water is used for industrial purposes. 50,000 gallons are consumed daily so industry consumes \( \frac{14}{100} \) x 50,000 gallons = 7,000 gallons.
Find the average of the following numbers: 15, 7, 12, 10.
| 11 | |
| 10 | |
| 15 | |
| 9 |
To find the average of these 4 numbers add them together then divide by 4:
\( \frac{15 + 7 + 12 + 10}{4} \) = \( \frac{44}{4} \) = 11