| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
Which of the following is not a prime number?
2 |
|
5 |
|
7 |
|
9 |
A prime number is an integer greater than 1 that has no factors other than 1 and itself. Examples of prime numbers include 2, 3, 5, 7, and 11.
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 5% off." If Charlie buys two shirts, each with a regular price of $26, how much money will he save?
| $1.30 | |
| $2.60 | |
| $11.70 | |
| $6.50 |
By buying two shirts, Charlie will save $26 x \( \frac{5}{100} \) = \( \frac{$26 x 5}{100} \) = \( \frac{$130}{100} \) = $1.30 on the second shirt.
What is the distance in miles of a trip that takes 3 hours at an average speed of 50 miles per hour?
| 150 miles | |
| 120 miles | |
| 270 miles | |
| 140 miles |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for distance:
distance = \( \text{speed} \times \text{time} \)
distance = \( 50mph \times 3h \)
150 miles
A machine in a factory has an error rate of 2 parts per 100. The machine normally runs 24 hours a day and produces 6 parts per hour. Yesterday the machine was shut down for 9 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 176.7 | |
| 69 | |
| 85.5 | |
| 88.2 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{2}{100} \) x 6 = \( \frac{2 \times 6}{100} \) = \( \frac{12}{100} \) = 0.12 errors per hour
So, in an average hour, the machine will produce 6 - 0.12 = 5.88 error free parts.
The machine ran for 24 - 9 = 15 hours yesterday so you would expect that 15 x 5.88 = 88.2 error free parts were produced yesterday.
If all of a roofing company's 6 workers are required to staff 3 roofing crews, how many workers need to be added during the busy season in order to send 5 complete crews out on jobs?
| 9 | |
| 6 | |
| 4 | |
| 14 |
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 6 workers at the company now and that's enough to staff 3 crews so there are \( \frac{6}{3} \) = 2 workers on a crew. 5 crews are needed for the busy season which, at 2 workers per crew, means that the roofing company will need 5 x 2 = 10 total workers to staff the crews during the busy season. The company already employs 6 workers so they need to add 10 - 6 = 4 new staff for the busy season.