| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.79 |
| Score | 0% | 56% |
What is 8\( \sqrt{3} \) x 8\( \sqrt{4} \)?
| 16\( \sqrt{3} \) | |
| 64\( \sqrt{4} \) | |
| 64\( \sqrt{3} \) | |
| 128\( \sqrt{3} \) |
To multiply terms with radicals, multiply the coefficients and radicands separately:
8\( \sqrt{3} \) x 8\( \sqrt{4} \)
(8 x 8)\( \sqrt{3 \times 4} \)
64\( \sqrt{12} \)
Now we need to simplify the radical:
64\( \sqrt{12} \)
64\( \sqrt{3 \times 4} \)
64\( \sqrt{3 \times 2^2} \)
(64)(2)\( \sqrt{3} \)
128\( \sqrt{3} \)
A machine in a factory has an error rate of 5 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 8 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 90.3 | |
| 98.7 | |
| 141.4 | |
| 152 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{5}{100} \) x 10 = \( \frac{5 \times 10}{100} \) = \( \frac{50}{100} \) = 0.5 errors per hour
So, in an average hour, the machine will produce 10 - 0.5 = 9.5 error free parts.
The machine ran for 24 - 8 = 16 hours yesterday so you would expect that 16 x 9.5 = 152 error free parts were produced yesterday.
What is the greatest common factor of 80 and 28?
| 21 | |
| 25 | |
| 4 | |
| 24 |
The factors of 80 are [1, 2, 4, 5, 8, 10, 16, 20, 40, 80] and the factors of 28 are [1, 2, 4, 7, 14, 28]. They share 3 factors [1, 2, 4] making 4 the greatest factor 80 and 28 have in common.
What is \( \frac{4z^6}{2z^2} \)?
| \(\frac{1}{2}\)z8 | |
| 2z4 | |
| 2z-4 | |
| 2z8 |
To divide terms with exponents, the base of both exponents must be the same. In this case they are so divide the coefficients and subtract the exponents:
\( \frac{4z^6}{2z^2} \)
\( \frac{4}{2} \) z(6 - 2)
2z4
If a mayor is elected with 56% of the votes cast and 55% of a town's 40,000 voters cast a vote, how many votes did the mayor receive?
| 12,320 | |
| 16,720 | |
| 13,200 | |
| 13,420 |
If 55% of the town's 40,000 voters cast ballots the number of votes cast is:
(\( \frac{55}{100} \)) x 40,000 = \( \frac{2,200,000}{100} \) = 22,000
The mayor got 56% of the votes cast which is:
(\( \frac{56}{100} \)) x 22,000 = \( \frac{1,232,000}{100} \) = 12,320 votes.