| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.15 |
| Score | 0% | 63% |
If \( \left|b - 8\right| \) - 9 = -8, which of these is a possible value for b?
| -8 | |
| 5 | |
| -2 | |
| 7 |
First, solve for \( \left|b - 8\right| \):
\( \left|b - 8\right| \) - 9 = -8
\( \left|b - 8\right| \) = -8 + 9
\( \left|b - 8\right| \) = 1
The value inside the absolute value brackets can be either positive or negative so (b - 8) must equal + 1 or -1 for \( \left|b - 8\right| \) to equal 1:
| b - 8 = 1 b = 1 + 8 b = 9 | b - 8 = -1 b = -1 + 8 b = 7 |
So, b = 7 or b = 9.
Solve 5 + (4 + 3) ÷ 3 x 5 - 52
| -8\(\frac{1}{3}\) | |
| \(\frac{2}{3}\) | |
| 1\(\frac{1}{6}\) | |
| \(\frac{1}{3}\) |
Use PEMDAS (Parentheses, Exponents, Multipy/Divide, Add/Subtract):
5 + (4 + 3) ÷ 3 x 5 - 52
P: 5 + (7) ÷ 3 x 5 - 52
E: 5 + 7 ÷ 3 x 5 - 25
MD: 5 + \( \frac{7}{3} \) x 5 - 25
MD: 5 + \( \frac{35}{3} \) - 25
AS: \( \frac{15}{3} \) + \( \frac{35}{3} \) - 25
AS: \( \frac{50}{3} \) - 25
AS: \( \frac{50 - 75}{3} \)
\( \frac{-25}{3} \)
-8\(\frac{1}{3}\)
Simplify \( \frac{20}{60} \).
| \( \frac{1}{3} \) | |
| \( \frac{4}{7} \) | |
| \( \frac{10}{19} \) | |
| \( \frac{9}{11} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 20 are [1, 2, 4, 5, 10, 20] and the factors of 60 are [1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60]. They share 6 factors [1, 2, 4, 5, 10, 20] making 20 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{20}{60} \) = \( \frac{\frac{20}{20}}{\frac{60}{20}} \) = \( \frac{1}{3} \)
The total water usage for a city is 50,000 gallons each day. Of that total, 32% is for personal use and 51% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 1,600 | |
| 11,500 | |
| 9,500 | |
| 5,200 |
51% of the water consumption is industrial use and 32% is personal use so (51% - 32%) = 19% more water is used for industrial purposes. 50,000 gallons are consumed daily so industry consumes \( \frac{19}{100} \) x 50,000 gallons = 9,500 gallons.
Which of the following is not a prime number?
7 |
|
2 |
|
9 |
|
5 |
A prime number is an integer greater than 1 that has no factors other than 1 and itself. Examples of prime numbers include 2, 3, 5, 7, and 11.