| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 6 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 155.6 | |
| 132.5 | |
| 99.8 | |
| 146.3 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{8}{100} \) x 8 = \( \frac{8 \times 8}{100} \) = \( \frac{64}{100} \) = 0.64 errors per hour
So, in an average hour, the machine will produce 8 - 0.64 = 7.36 error free parts.
The machine ran for 24 - 6 = 18 hours yesterday so you would expect that 18 x 7.36 = 132.5 error free parts were produced yesterday.
Betty scored 81% on her final exam. If each question was worth 3 points and there were 300 possible points on the exam, how many questions did Betty answer correctly?
| 93 | |
| 91 | |
| 81 | |
| 76 |
Betty scored 81% on the test meaning she earned 81% of the possible points on the test. There were 300 possible points on the test so she earned 300 x 0.81 = 243 points. Each question is worth 3 points so she got \( \frac{243}{3} \) = 81 questions right.
Which of these numbers is a factor of 24?
| 8 | |
| 19 | |
| 20 | |
| 10 |
The factors of a number are all positive integers that divide evenly into the number. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24.
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 20% off." If Charlie buys two shirts, each with a regular price of $24, how much money will he save?
| 29 | |
| $4.80 | |
| $6.00 | |
| $10.80 |
By buying two shirts, Charlie will save $24 x \( \frac{20}{100} \) = \( \frac{$24 x 20}{100} \) = \( \frac{$480}{100} \) = $4.80 on the second shirt.
Ezra loaned Ezra $1,400 at an annual interest rate of 5%. If no payments are made, what is the interest owed on this loan at the end of the first year?
| $24 | |
| $12 | |
| $99 | |
| $70 |
The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:
interest = annual interest rate x loan amount
i = (\( \frac{6}{100} \)) x $1,400
i = 0.05 x $1,400
i = $70