| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
A circular logo is enlarged to fit the lid of a jar. The new diameter is 45% larger than the original. By what percentage has the area of the logo increased?
| 25% | |
| 22\(\frac{1}{2}\)% | |
| 37\(\frac{1}{2}\)% | |
| 15% |
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 45% the radius (and, consequently, the total area) increases by \( \frac{45\text{%}}{2} \) = 22\(\frac{1}{2}\)%
What is \( \frac{1}{7} \) x \( \frac{1}{6} \)?
| \(\frac{1}{42}\) | |
| \(\frac{1}{4}\) | |
| \(\frac{1}{3}\) | |
| \(\frac{4}{27}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{1}{7} \) x \( \frac{1}{6} \) = \( \frac{1 x 1}{7 x 6} \) = \( \frac{1}{42} \) = \(\frac{1}{42}\)
Solve for \( \frac{4!}{3!} \)
| 1680 | |
| 4 | |
| \( \frac{1}{30} \) | |
| 56 |
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:
\( \frac{4!}{3!} \)
\( \frac{4 \times 3 \times 2 \times 1}{3 \times 2 \times 1} \)
\( \frac{4}{1} \)
4
What is the least common multiple of 4 and 10?
| 18 | |
| 20 | |
| 22 | |
| 16 |
The first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [20, 40, 60, 80] making 20 the smallest multiple 4 and 10 have in common.
What is \( \frac{-1z^8}{6z^2} \)?
| -\(\frac{1}{6}\)z6 | |
| -6z-6 | |
| -6z6 | |
| -\(\frac{1}{6}\)z\(\frac{1}{4}\) |
To divide terms with exponents, the base of both exponents must be the same. In this case they are so divide the coefficients and subtract the exponents:
\( \frac{-z^8}{6z^2} \)
\( \frac{-1}{6} \) z(8 - 2)
-\(\frac{1}{6}\)z6