| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 9 parts per hour. Yesterday the machine was shut down for 8 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 132.5 | |
| 142.9 | |
| 121.4 | |
| 141.1 |
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 9 = \( \frac{8 \times 9}{100} \) = \( \frac{72}{100} \) = 0.72 errors per hour
So, in an average hour, the machine will produce 9 - 0.72 = 8.28 error free parts.
The machine ran for 24 - 8 = 16 hours yesterday so you would expect that 16 x 8.28 = 132.5 error free parts were produced yesterday.
What is 2\( \sqrt{9} \) x 4\( \sqrt{9} \)?
| 24\( \sqrt{9} \) | |
| 6\( \sqrt{81} \) | |
| 8\( \sqrt{9} \) | |
| 8\( \sqrt{18} \) |
To multiply terms with radicals, multiply the coefficients and radicands separately:
2\( \sqrt{9} \) x 4\( \sqrt{9} \)
(2 x 4)\( \sqrt{9 \times 9} \)
8\( \sqrt{81} \)
Now we need to simplify the radical:
8\( \sqrt{81} \)
8\( \sqrt{9 \times 9} \)
8\( \sqrt{9 \times 3^2} \)
(8)(3)\( \sqrt{9} \)
24\( \sqrt{9} \)
\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
commutative property for multiplication |
|
distributive property for division |
|
distributive property for multiplication |
|
commutative property for division |
The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).
What is \( \frac{4\sqrt{21}}{2\sqrt{3}} \)?
| 7 \( \sqrt{2} \) | |
| 2 \( \sqrt{7} \) | |
| \(\frac{1}{7}\) \( \sqrt{2} \) | |
| \(\frac{1}{7}\) \( \sqrt{\frac{1}{2}} \) |
To divide terms with radicals, divide the coefficients and radicands separately:
\( \frac{4\sqrt{21}}{2\sqrt{3}} \)
\( \frac{4}{2} \) \( \sqrt{\frac{21}{3}} \)
2 \( \sqrt{7} \)
What is (a4)2?
| a8 | |
| a2 | |
| a-2 | |
| a6 |
To raise a term with an exponent to another exponent, retain the base and multiply the exponents:
(a4)2