| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.92 |
| Score | 0% | 58% |
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 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 75.2 | |
| 192 | |
| 164.9 | |
| 170.7 |
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 - 2 = 22 hours yesterday so you would expect that 22 x 7.76 = 170.7 error free parts were produced yesterday.
A tiger in a zoo has consumed 35 pounds of food in 7 days. If the tiger continues to eat at the same rate, in how many more days will its total food consumtion be 50 pounds?
| 4 | |
| 8 | |
| 9 | |
| 3 |
If the tiger has consumed 35 pounds of food in 7 days that's \( \frac{35}{7} \) = 5 pounds of food per day. The tiger needs to consume 50 - 35 = 15 more pounds of food to reach 50 pounds total. At 5 pounds of food per day that's \( \frac{15}{5} \) = 3 more days.
This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
distributive |
|
commutative |
|
PEDMAS |
|
associative |
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.
Which of the following is an improper fraction?
\({7 \over 5} \) |
|
\(1 {2 \over 5} \) |
|
\({a \over 5} \) |
|
\({2 \over 5} \) |
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 all of a roofing company's 15 workers are required to staff 5 roofing crews, how many workers need to be added during the busy season in order to send 8 complete crews out on jobs?
| 1 | |
| 2 | |
| 11 | |
| 9 |
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 15 workers at the company now and that's enough to staff 5 crews so there are \( \frac{15}{5} \) = 3 workers on a crew. 8 crews are needed for the busy season which, at 3 workers per crew, means that the roofing company will need 8 x 3 = 24 total workers to staff the crews during the busy season. The company already employs 15 workers so they need to add 24 - 15 = 9 new staff for the busy season.