| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 or a = -7 |
|
a = 7 |
|
none of these is correct |
|
a = -7 |
The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 40% off." If Roger buys two shirts, each with a regular price of $10, how much will he pay for both shirts?
| $16.00 | |
| $10.50 | |
| $4.00 | |
| $11.50 |
By buying two shirts, Roger will save $10 x \( \frac{40}{100} \) = \( \frac{$10 x 40}{100} \) = \( \frac{$400}{100} \) = $4.00 on the second shirt.
So, his total cost will be
$10.00 + ($10.00 - $4.00)
$10.00 + $6.00
$16.00
A machine in a factory has an error rate of 6 parts per 100. The machine normally runs 24 hours a day and produces 9 parts per hour. Yesterday the machine was shut down for 6 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 172 | |
| 152.3 | |
| 132.5 | |
| 142.9 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{6}{100} \) x 9 = \( \frac{6 \times 9}{100} \) = \( \frac{54}{100} \) = 0.54 errors per hour
So, in an average hour, the machine will produce 9 - 0.54 = 8.46 error free parts.
The machine ran for 24 - 6 = 18 hours yesterday so you would expect that 18 x 8.46 = 152.3 error free parts were produced yesterday.
Simplify \( \sqrt{48} \)
| 4\( \sqrt{3} \) | |
| 3\( \sqrt{6} \) | |
| 5\( \sqrt{6} \) | |
| 9\( \sqrt{6} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{48} \)
\( \sqrt{16 \times 3} \)
\( \sqrt{4^2 \times 3} \)
4\( \sqrt{3} \)
4! = ?
4 x 3 |
|
3 x 2 x 1 |
|
5 x 4 x 3 x 2 x 1 |
|
4 x 3 x 2 x 1 |
A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.