| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
Which of the following is not a prime number?
5 |
|
9 |
|
2 |
|
7 |
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 machine in a factory has an error rate of 4 parts per 100. The machine normally runs 24 hours a day and produces 5 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 150.7 | |
| 85.5 | |
| 96 | |
| 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:
\( \frac{4}{100} \) x 5 = \( \frac{4 \times 5}{100} \) = \( \frac{20}{100} \) = 0.2 errors per hour
So, in an average hour, the machine will produce 5 - 0.2 = 4.8 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 4.8 = 96 error free parts were produced yesterday.
If the ratio of home fans to visiting fans in a crowd is 3:1 and all 47,000 seats in a stadium are filled, how many home fans are in attendance?
| 35,250 | |
| 24,800 | |
| 24,000 | |
| 27,200 |
A ratio of 3:1 means that there are 3 home fans for every one visiting fan. So, of every 4 fans, 3 are home fans and \( \frac{3}{4} \) of every fan in the stadium is a home fan:
47,000 fans x \( \frac{3}{4} \) = \( \frac{141000}{4} \) = 35,250 fans.
What is the next number in this sequence: 1, 5, 13, 25, 41, __________ ?
| 58 | |
| 67 | |
| 59 | |
| 61 |
The equation for this sequence is:
an = an-1 + 4(n - 1)
where n is the term's order in the sequence, an is the value of the term, and an-1 is the value of the term before an. This makes the next number:
a6 = a5 + 4(6 - 1)
a6 = 41 + 4(5)
a6 = 61
In a class of 31 students, 11 are taking German and 14 are taking Spanish. Of the students studying German or Spanish, 4 are taking both courses. How many students are not enrolled in either course?
| 24 | |
| 18 | |
| 27 | |
| 10 |
The number of students taking German or Spanish is 11 + 14 = 25. Of that group of 25, 4 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 25 - 4 = 21 who are taking at least one language. 31 - 21 = 10 students who are not taking either language.