| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.36 |
| Score | 0% | 67% |
A machine in a factory has an error rate of 7 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?
| 117.6 | |
| 148.8 | |
| 73.5 | |
| 139.5 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 8 = \( \frac{7 \times 8}{100} \) = \( \frac{56}{100} \) = 0.56 errors per hour
So, in an average hour, the machine will produce 8 - 0.56 = 7.4399999999999995 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 7.4399999999999995 = 148.8 error free parts were produced yesterday.
Which of the following is not a prime number?
7 |
|
2 |
|
5 |
|
9 |
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.
A factor is a positive __________ that divides evenly into a given number.
improper fraction |
|
fraction |
|
integer |
|
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 tiger in a zoo has consumed 72 pounds of food in 6 days. If the tiger continues to eat at the same rate, in how many more days will its total food consumtion be 108 pounds?
| 3 | |
| 2 | |
| 8 | |
| 1 |
If the tiger has consumed 72 pounds of food in 6 days that's \( \frac{72}{6} \) = 12 pounds of food per day. The tiger needs to consume 108 - 72 = 36 more pounds of food to reach 108 pounds total. At 12 pounds of food per day that's \( \frac{36}{12} \) = 3 more days.
If a car travels 75 miles in 3 hours, what is the average speed?
| 60 mph | |
| 25 mph | |
| 45 mph | |
| 30 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)