| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
If a rectangle is twice as long as it is wide and has a perimeter of 24 meters, what is the area of the rectangle?
| 162 m2 | |
| 98 m2 | |
| 32 m2 | |
| 50 m2 |
The area of a rectangle is width (w) x height (h). In this problem we know that the rectangle is twice as long as it is wide so h = 2w. The perimeter of a rectangle is 2w + 2h and we know that the perimeter of this rectangle is 24 meters so the equation becomes: 2w + 2h = 24.
Putting these two equations together and solving for width (w):
2w + 2h = 24
w + h = \( \frac{24}{2} \)
w + h = 12
w = 12 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 12 - 2w
3w = 12
w = \( \frac{12}{3} \)
w = 4
Since h = 2w that makes h = (2 x 4) = 8 and the area = h x w = 4 x 8 = 32 m2
Simplify \( \frac{40}{44} \).
| \( \frac{2}{5} \) | |
| \( \frac{1}{4} \) | |
| \( \frac{6}{19} \) | |
| \( \frac{10}{11} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 40 are [1, 2, 4, 5, 8, 10, 20, 40] and the factors of 44 are [1, 2, 4, 11, 22, 44]. They share 3 factors [1, 2, 4] making 4 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{40}{44} \) = \( \frac{\frac{40}{4}}{\frac{44}{4}} \) = \( \frac{10}{11} \)
If the ratio of home fans to visiting fans in a crowd is 3:1 and all 38,000 seats in a stadium are filled, how many home fans are in attendance?
| 35,833 | |
| 26,400 | |
| 33,333 | |
| 28,500 |
A ratio of 3:1 means that there are 3 home fans for every one visiting fan. So, of every 4 fans, 3 are home fans and \( \frac{3}{4} \) of every fan in the stadium is a home fan:
38,000 fans x \( \frac{3}{4} \) = \( \frac{114000}{4} \) = 28,500 fans.
If \( \left|c - 9\right| \) - 7 = 7, which of these is a possible value for c?
| 6 | |
| 0 | |
| 4 | |
| 23 |
First, solve for \( \left|c - 9\right| \):
\( \left|c - 9\right| \) - 7 = 7
\( \left|c - 9\right| \) = 7 + 7
\( \left|c - 9\right| \) = 14
The value inside the absolute value brackets can be either positive or negative so (c - 9) must equal + 14 or -14 for \( \left|c - 9\right| \) to equal 14:
| c - 9 = 14 c = 14 + 9 c = 23 | c - 9 = -14 c = -14 + 9 c = -5 |
So, c = -5 or c = 23.
Convert c-5 to remove the negative exponent.
| \( \frac{-1}{c^{-5}} \) | |
| \( \frac{1}{c^{-5}} \) | |
| \( \frac{-5}{c} \) | |
| \( \frac{1}{c^5} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.