| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.67 |
| Score | 0% | 53% |
Solve for \( \frac{3!}{4!} \)
| 42 | |
| \( \frac{1}{4} \) | |
| \( \frac{1}{1680} \) | |
| 336 |
A factorial is the product of an integer and all the positive integers below it. To solve a fraction featuring factorials, expand the factorials and cancel out like numbers:
\( \frac{3!}{4!} \)
\( \frac{3 \times 2 \times 1}{4 \times 3 \times 2 \times 1} \)
\( \frac{1}{4} \)
\( \frac{1}{4} \)
What is 2\( \sqrt{8} \) x 3\( \sqrt{8} \)?
| 48 | |
| 5\( \sqrt{64} \) | |
| 6\( \sqrt{16} \) | |
| 5\( \sqrt{8} \) |
To multiply terms with radicals, multiply the coefficients and radicands separately:
2\( \sqrt{8} \) x 3\( \sqrt{8} \)
(2 x 3)\( \sqrt{8 \times 8} \)
6\( \sqrt{64} \)
Now we need to simplify the radical:
6\( \sqrt{64} \)
6\( \sqrt{8^2} \)
(6)(8)
48
Simplify \( \sqrt{112} \)
| 4\( \sqrt{7} \) | |
| 4\( \sqrt{14} \) | |
| 5\( \sqrt{7} \) | |
| 9\( \sqrt{14} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{112} \)
\( \sqrt{16 \times 7} \)
\( \sqrt{4^2 \times 7} \)
4\( \sqrt{7} \)
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?
| 72 m2 | |
| 98 m2 | |
| 32 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 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
A circular logo is enlarged to fit the lid of a jar. The new diameter is 50% larger than the original. By what percentage has the area of the logo increased?
| 25% | |
| 15% | |
| 32\(\frac{1}{2}\)% | |
| 37\(\frac{1}{2}\)% |
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 50% the radius (and, consequently, the total area) increases by \( \frac{50\text{%}}{2} \) = 25%