| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.87 |
| Score | 0% | 57% |
A machine in a factory has an error rate of 3 parts per 100. The machine normally runs 24 hours a day and produces 5 parts per hour. Yesterday the machine was shut down for 4 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 148.8 | |
| 144.4 | |
| 192.1 | |
| 97 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{3}{100} \) x 5 = \( \frac{3 \times 5}{100} \) = \( \frac{15}{100} \) = 0.15 errors per hour
So, in an average hour, the machine will produce 5 - 0.15 = 4.85 error free parts.
The machine ran for 24 - 4 = 20 hours yesterday so you would expect that 20 x 4.85 = 97 error free parts were produced yesterday.
a(b + c) = ab + ac defines which of the following?
commutative property for division |
|
distributive property for multiplication |
|
distributive property for division |
|
commutative property for multiplication |
The distributive property for multiplication helps in solving expressions like a(b + c). It specifies that the result of multiplying one number by the sum or difference of two numbers can be obtained by multiplying each number individually and then totaling the results: a(b + c) = ab + ac. For example, 4(10-5) = (4 x 10) - (4 x 5) = 40 - 20 = 20.
If a mayor is elected with 67% of the votes cast and 66% of a town's 11,000 voters cast a vote, how many votes did the mayor receive?
| 4,864 | |
| 4,138 | |
| 5,518 | |
| 5,735 |
If 66% of the town's 11,000 voters cast ballots the number of votes cast is:
(\( \frac{66}{100} \)) x 11,000 = \( \frac{726,000}{100} \) = 7,260
The mayor got 67% of the votes cast which is:
(\( \frac{67}{100} \)) x 7,260 = \( \frac{486,420}{100} \) = 4,864 votes.
What is -9b7 - 4b7?
| -13b7 | |
| 13b7 | |
| 13b-7 | |
| -5b14 |
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:
-9b7 - 4b7
(-9 - 4)b7
-13b7
On average, the center for a basketball team hits 25% of his shots while a guard on the same team hits 45% of his shots. If the guard takes 25 shots during a game, how many shots will the center have to take to score as many points as the guard assuming each shot is worth the same number of points?
| 55 | |
| 24 | |
| 44 | |
| 26 |
guard shots made = shots taken x \( \frac{\text{% made}}{100} \) = 25 x \( \frac{45}{100} \) = \( \frac{45 x 25}{100} \) = \( \frac{1125}{100} \) = 11 shots
The center makes 25% of his shots so he'll have to take:
shots made = shots taken x \( \frac{\text{% made}}{100} \)
shots taken = \( \frac{\text{shots taken}}{\frac{\text{% made}}{100}} \)
to make as many shots as the guard. Plugging in values for the center gives us:
center shots taken = \( \frac{11}{\frac{25}{100}} \) = 11 x \( \frac{100}{25} \) = \( \frac{11 x 100}{25} \) = \( \frac{1100}{25} \) = 44 shots
to make the same number of shots as the guard and thus score the same number of points.