| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.06 |
| Score | 0% | 61% |
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 6 parts per hour. Yesterday the machine was shut down for 3 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 167.4 | |
| 115.9 | |
| 150.9 | |
| 84.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{8}{100} \) x 6 = \( \frac{8 \times 6}{100} \) = \( \frac{48}{100} \) = 0.48 errors per hour
So, in an average hour, the machine will produce 6 - 0.48 = 5.52 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 5.52 = 115.9 error free parts were produced yesterday.
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 35% off." If Frank buys two shirts, each with a regular price of $33, how much will he pay for both shirts?
| $46.20 | |
| $21.45 | |
| $11.55 | |
| $54.45 |
By buying two shirts, Frank will save $33 x \( \frac{35}{100} \) = \( \frac{$33 x 35}{100} \) = \( \frac{$1155}{100} \) = $11.55 on the second shirt.
So, his total cost will be
$33.00 + ($33.00 - $11.55)
$33.00 + $21.45
$54.45
In a class of 29 students, 13 are taking German and 15 are taking Spanish. Of the students studying German or Spanish, 7 are taking both courses. How many students are not enrolled in either course?
| 8 | |
| 13 | |
| 28 | |
| 16 |
The number of students taking German or Spanish is 13 + 15 = 28. Of that group of 28, 7 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 28 - 7 = 21 who are taking at least one language. 29 - 21 = 8 students who are not taking either language.
A triathlon course includes a 400m swim, a 20.9km bike ride, and a 9.7km run. What is the total length of the race course?
| 37.1km | |
| 36.8km | |
| 31km | |
| 65.7km |
To add these distances, they must share the same unit so first you need to first convert the swim distance from meters (m) to kilometers (km) before adding it to the bike and run distances which are already in km. To convert 400 meters to kilometers, divide the distance by 1000 to get 0.4km then add the remaining distances:
total distance = swim + bike + run
total distance = 0.4km + 20.9km + 9.7km
total distance = 31km
What is the next number in this sequence: 1, 5, 13, 25, 41, __________ ?
| 69 | |
| 67 | |
| 61 | |
| 57 |
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