| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
Which of the following is not a prime number?
9 |
|
5 |
|
7 |
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2 |
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.
If a rectangle is twice as long as it is wide and has a perimeter of 48 meters, what is the area of the rectangle?
| 72 m2 | |
| 50 m2 | |
| 18 m2 | |
| 128 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 48 meters so the equation becomes: 2w + 2h = 48.
Putting these two equations together and solving for width (w):
2w + 2h = 48
w + h = \( \frac{48}{2} \)
w + h = 24
w = 24 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 24 - 2w
3w = 24
w = \( \frac{24}{3} \)
w = 8
Since h = 2w that makes h = (2 x 8) = 16 and the area = h x w = 8 x 16 = 128 m2
What is \( \frac{3}{9} \) ÷ \( \frac{4}{9} \)?
| \(\frac{3}{40}\) | |
| 6\(\frac{3}{4}\) | |
| \(\frac{3}{4}\) | |
| 3 |
To divide fractions, invert the second fraction and then multiply:
\( \frac{3}{9} \) ÷ \( \frac{4}{9} \) = \( \frac{3}{9} \) x \( \frac{9}{4} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{3}{9} \) x \( \frac{9}{4} \) = \( \frac{3 x 9}{9 x 4} \) = \( \frac{27}{36} \) = \(\frac{3}{4}\)
What is \( 4 \)\( \sqrt{112} \) - \( 6 \)\( \sqrt{7} \)
| -2\( \sqrt{112} \) | |
| 10\( \sqrt{7} \) | |
| -2\( \sqrt{33} \) | |
| -2\( \sqrt{7} \) |
To subtract these radicals together their radicands must be the same:
4\( \sqrt{112} \) - 6\( \sqrt{7} \)
4\( \sqrt{16 \times 7} \) - 6\( \sqrt{7} \)
4\( \sqrt{4^2 \times 7} \) - 6\( \sqrt{7} \)
(4)(4)\( \sqrt{7} \) - 6\( \sqrt{7} \)
16\( \sqrt{7} \) - 6\( \sqrt{7} \)
Now that the radicands are identical, you can subtract them:
16\( \sqrt{7} \) - 6\( \sqrt{7} \)What is \( \sqrt{\frac{9}{36}} \)?
| \(\frac{2}{3}\) | |
| \(\frac{2}{7}\) | |
| \(\frac{1}{2}\) | |
| 2 |
To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:
\( \sqrt{\frac{9}{36}} \)
\( \frac{\sqrt{9}}{\sqrt{36}} \)
\( \frac{\sqrt{3^2}}{\sqrt{6^2}} \)
\(\frac{1}{2}\)