| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.56 |
| Score | 0% | 71% |
What is 7c4 - 6c4?
| -c4 | |
| c4 | |
| c-4 | |
| 13c8 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:
7c4 - 6c4
(7 - 6)c4
c4
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 40% off." If Charlie buys two shirts, each with a regular price of $39, how much money will he save?
| $11.70 | |
| $15.60 | |
| $19.50 | |
| $3.90 |
By buying two shirts, Charlie will save $39 x \( \frac{40}{100} \) = \( \frac{$39 x 40}{100} \) = \( \frac{$1560}{100} \) = $15.60 on the second shirt.
A factor is a positive __________ that divides evenly into a given number.
integer |
|
fraction |
|
mixed number |
|
improper fraction |
A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.
4! = ?
5 x 4 x 3 x 2 x 1 |
|
3 x 2 x 1 |
|
4 x 3 x 2 x 1 |
|
4 x 3 |
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.
A machine in a factory has an error rate of 7 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 163.7 | |
| 103 | |
| 141.7 | |
| 215.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 8 = \( \frac{7 \times 8}{100} \) = \( \frac{56}{100} \) = 0.56 errors per hour
So, in an average hour, the machine will produce 8 - 0.56 = 7.4399999999999995 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 7.4399999999999995 = 163.7 error free parts were produced yesterday.