| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.99 |
| Score | 0% | 60% |
What is -2c5 x 3c6?
| c30 | |
| -6c11 | |
| -6c30 | |
| -6c6 |
To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:
-2c5 x 3c6
(-2 x 3)c(5 + 6)
-6c11
If a rectangle is twice as long as it is wide and has a perimeter of 30 meters, what is the area of the rectangle?
| 18 m2 | |
| 50 m2 | |
| 162 m2 | |
| 2 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 30 meters so the equation becomes: 2w + 2h = 30.
Putting these two equations together and solving for width (w):
2w + 2h = 30
w + h = \( \frac{30}{2} \)
w + h = 15
w = 15 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 15 - 2w
3w = 15
w = \( \frac{15}{3} \)
w = 5
Since h = 2w that makes h = (2 x 5) = 10 and the area = h x w = 5 x 10 = 50 m2
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.
What is \( \frac{8}{6} \) - \( \frac{9}{12} \)?
| 2 \( \frac{7}{12} \) | |
| \( \frac{6}{9} \) | |
| 2 \( \frac{2}{12} \) | |
| \(\frac{7}{12}\) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [12, 24, 36, 48, 60] making 12 the smallest multiple 6 and 12 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{8 x 2}{6 x 2} \) - \( \frac{9 x 1}{12 x 1} \)
\( \frac{16}{12} \) - \( \frac{9}{12} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{16 - 9}{12} \) = \( \frac{7}{12} \) = \(\frac{7}{12}\)
A circular logo is enlarged to fit the lid of a jar. The new diameter is 60% larger than the original. By what percentage has the area of the logo increased?
| 30% | |
| 17\(\frac{1}{2}\)% | |
| 27\(\frac{1}{2}\)% | |
| 22\(\frac{1}{2}\)% |
The area of a circle is given by the formula A = πr2 where r is the radius of the circle. The radius of a circle is its diameter divided by two so A = π(\( \frac{d}{2} \))2. If the diameter of the logo increases by 60% the radius (and, consequently, the total area) increases by \( \frac{60\text{%}}{2} \) = 30%