| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
April scored 80% on her final exam. If each question was worth 3 points and there were 150 possible points on the exam, how many questions did April answer correctly?
| 49 | |
| 52 | |
| 40 | |
| 41 |
April scored 80% on the test meaning she earned 80% of the possible points on the test. There were 150 possible points on the test so she earned 150 x 0.8 = 120 points. Each question is worth 3 points so she got \( \frac{120}{3} \) = 40 questions right.
Which of the following is an improper fraction?
\({a \over 5} \) |
|
\({2 \over 5} \) |
|
\({7 \over 5} \) |
|
\(1 {2 \over 5} \) |
A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.
Simplify \( \frac{32}{80} \).
| \( \frac{5}{7} \) | |
| \( \frac{3}{7} \) | |
| \( \frac{2}{5} \) | |
| \( \frac{9}{19} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 32 are [1, 2, 4, 8, 16, 32] and the factors of 80 are [1, 2, 4, 5, 8, 10, 16, 20, 40, 80]. They share 5 factors [1, 2, 4, 8, 16] making 16 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{32}{80} \) = \( \frac{\frac{32}{16}}{\frac{80}{16}} \) = \( \frac{2}{5} \)
If a car travels 200 miles in 8 hours, what is the average speed?
| 25 mph | |
| 70 mph | |
| 60 mph | |
| 65 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)A machine in a factory has an error rate of 2 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 127.8 | |
| 172.5 | |
| 136.5 | |
| 163.8 |
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 8 = \( \frac{2 \times 8}{100} \) = \( \frac{16}{100} \) = 0.16 errors per hour
So, in an average hour, the machine will produce 8 - 0.16 = 7.84 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 7.84 = 172.5 error free parts were produced yesterday.