| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.17 |
| Score | 0% | 63% |
Which of the following is an improper fraction?
\({2 \over 5} \) |
|
\({a \over 5} \) |
|
\({7 \over 5} \) |
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\(1 {2 \over 5} \) |
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.
If a car travels 30 miles in 2 hours, what is the average speed?
| 60 mph | |
| 65 mph | |
| 55 mph | |
| 15 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
commutative |
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associative |
|
distributive |
|
PEDMAS |
The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.
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 6 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 155.6 | |
| 156.4 | |
| 141.1 | |
| 86.5 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{2}{100} \) 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 - 6 = 18 hours yesterday so you would expect that 18 x 7.84 = 141.1 error free parts were produced yesterday.
If a mayor is elected with 79% of the votes cast and 80% of a town's 15,000 voters cast a vote, how many votes did the mayor receive?
| 6,120 | |
| 9,120 | |
| 8,280 | |
| 9,480 |
If 80% of the town's 15,000 voters cast ballots the number of votes cast is:
(\( \frac{80}{100} \)) x 15,000 = \( \frac{1,200,000}{100} \) = 12,000
The mayor got 79% of the votes cast which is:
(\( \frac{79}{100} \)) x 12,000 = \( \frac{948,000}{100} \) = 9,480 votes.