| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.02 |
| Score | 0% | 60% |
If there were a total of 350 raffle tickets sold and you bought 17 tickets, what's the probability that you'll win the raffle?
| 5% | |
| 6% | |
| 4% | |
| 15% |
You have 17 out of the total of 350 raffle tickets sold so you have a (\( \frac{17}{350} \)) x 100 = \( \frac{17 \times 100}{350} \) = \( \frac{1700}{350} \) = 5% chance to win the raffle.
What is \( \frac{21\sqrt{4}}{7\sqrt{2}} \)?
| \(\frac{1}{3}\) \( \sqrt{\frac{1}{2}} \) | |
| 3 \( \sqrt{2} \) | |
| \(\frac{1}{3}\) \( \sqrt{2} \) | |
| 2 \( \sqrt{3} \) |
To divide terms with radicals, divide the coefficients and radicands separately:
\( \frac{21\sqrt{4}}{7\sqrt{2}} \)
\( \frac{21}{7} \) \( \sqrt{\frac{4}{2}} \)
3 \( \sqrt{2} \)
A machine in a factory has an error rate of 3 parts per 100. The machine normally runs 24 hours a day and produces 7 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 138.2 | |
| 98.3 | |
| 183.3 | |
| 135.8 |
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 7 = \( \frac{3 \times 7}{100} \) = \( \frac{21}{100} \) = 0.21 errors per hour
So, in an average hour, the machine will produce 7 - 0.21 = 6.79 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 6.79 = 135.8 error free parts were produced yesterday.
What is \( 8 \)\( \sqrt{175} \) + \( 7 \)\( \sqrt{7} \)
| 56\( \sqrt{1225} \) | |
| 15\( \sqrt{7} \) | |
| 15\( \sqrt{1225} \) | |
| 47\( \sqrt{7} \) |
To add these radicals together their radicands must be the same:
8\( \sqrt{175} \) + 7\( \sqrt{7} \)
8\( \sqrt{25 \times 7} \) + 7\( \sqrt{7} \)
8\( \sqrt{5^2 \times 7} \) + 7\( \sqrt{7} \)
(8)(5)\( \sqrt{7} \) + 7\( \sqrt{7} \)
40\( \sqrt{7} \) + 7\( \sqrt{7} \)
Now that the radicands are identical, you can add them together:
40\( \sqrt{7} \) + 7\( \sqrt{7} \)What is the distance in miles of a trip that takes 8 hours at an average speed of 20 miles per hour?
| 25 miles | |
| 160 miles | |
| 385 miles | |
| 390 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 = \( 20mph \times 8h \)
160 miles