| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.04 |
| Score | 0% | 61% |
What is \( \frac{3}{5} \) x \( \frac{4}{8} \)?
| \(\frac{1}{30}\) | |
| \(\frac{1}{10}\) | |
| \(\frac{4}{63}\) | |
| \(\frac{3}{10}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{3}{5} \) x \( \frac{4}{8} \) = \( \frac{3 x 4}{5 x 8} \) = \( \frac{12}{40} \) = \(\frac{3}{10}\)
A machine in a factory has an error rate of 6 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?
| 111.7 | |
| 160.7 | |
| 118.4 | |
| 88.2 |
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 6 = \( \frac{6 \times 6}{100} \) = \( \frac{36}{100} \) = 0.36 errors per hour
So, in an average hour, the machine will produce 6 - 0.36 = 5.64 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 5.64 = 118.4 error free parts were produced yesterday.
Which of the following statements about exponents is false?
b0 = 1 |
|
b1 = 1 |
|
all of these are false |
|
b1 = b |
A number with an exponent (be) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b1 = b) and a base with an exponent of 0 equals 1 ( (b0 = 1).
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 25% off." If Bob buys two shirts, each with a regular price of $17, how much money will he save?
| $7.65 | |
| $4.25 | |
| $3.40 | |
| $5.10 |
By buying two shirts, Bob will save $17 x \( \frac{25}{100} \) = \( \frac{$17 x 25}{100} \) = \( \frac{$425}{100} \) = $4.25 on the second shirt.
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
|
a = 7 |
|
none of these is correct |
|
a = 7 or 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).