| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.29 |
| Score | 0% | 66% |
A machine in a factory has an error rate of 3 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 8 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 124.2 | |
| 94 | |
| 116.6 | |
| 185.2 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{3}{100} \) x 8 = \( \frac{3 \times 8}{100} \) = \( \frac{24}{100} \) = 0.24 errors per hour
So, in an average hour, the machine will produce 8 - 0.24 = 7.76 error free parts.
The machine ran for 24 - 8 = 16 hours yesterday so you would expect that 16 x 7.76 = 124.2 error free parts were produced yesterday.
Which of the following is a mixed number?
\({7 \over 5} \) |
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\({5 \over 7} \) |
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\(1 {2 \over 5} \) |
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\({a \over 5} \) |
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.
A factor is a positive __________ that divides evenly into a given number.
integer |
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fraction |
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mixed number |
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improper fraction |
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.
If all of a roofing company's 8 workers are required to staff 4 roofing crews, how many workers need to be added during the busy season in order to send 6 complete crews out on jobs?
| 4 | |
| 13 | |
| 12 | |
| 10 |
In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 8 workers at the company now and that's enough to staff 4 crews so there are \( \frac{8}{4} \) = 2 workers on a crew. 6 crews are needed for the busy season which, at 2 workers per crew, means that the roofing company will need 6 x 2 = 12 total workers to staff the crews during the busy season. The company already employs 8 workers so they need to add 12 - 8 = 4 new staff for the busy season.
If there were a total of 200 raffle tickets sold and you bought 10 tickets, what's the probability that you'll win the raffle?
| 5% | |
| 11% | |
| 8% | |
| 14% |
You have 10 out of the total of 200 raffle tickets sold so you have a (\( \frac{10}{200} \)) x 100 = \( \frac{10 \times 100}{200} \) = \( \frac{1000}{200} \) = 5% chance to win the raffle.