| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
A circular logo is enlarged to fit the lid of a jar. The new diameter is 65% larger than the original. By what percentage has the area of the logo increased?
| 37\(\frac{1}{2}\)% | |
| 30% | |
| 27\(\frac{1}{2}\)% | |
| 32\(\frac{1}{2}\)% |
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 65% the radius (and, consequently, the total area) increases by \( \frac{65\text{%}}{2} \) = 32\(\frac{1}{2}\)%
What is the least common multiple of 5 and 9?
| 4 | |
| 25 | |
| 45 | |
| 19 |
The first few multiples of 5 are [5, 10, 15, 20, 25, 30, 35, 40, 45, 50] and the first few multiples of 9 are [9, 18, 27, 36, 45, 54, 63, 72, 81, 90]. The first few multiples they share are [45, 90] making 45 the smallest multiple 5 and 9 have in common.
If \( \left|z - 5\right| \) + 1 = 4, which of these is a possible value for z?
| 8 | |
| -3 | |
| -2 | |
| 5 |
First, solve for \( \left|z - 5\right| \):
\( \left|z - 5\right| \) + 1 = 4
\( \left|z - 5\right| \) = 4 - 1
\( \left|z - 5\right| \) = 3
The value inside the absolute value brackets can be either positive or negative so (z - 5) must equal + 3 or -3 for \( \left|z - 5\right| \) to equal 3:
| z - 5 = 3 z = 3 + 5 z = 8 | z - 5 = -3 z = -3 + 5 z = 2 |
So, z = 2 or z = 8.
The __________ is the greatest factor that divides two integers.
least common multiple |
|
absolute value |
|
greatest common multiple |
|
greatest common factor |
The greatest common factor (GCF) is the greatest factor that divides two integers.
Solve for \( \frac{3!}{2!} \)
| 3 | |
| 210 | |
| 5 | |
| \( \frac{1}{9} \) |
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:
\( \frac{3!}{2!} \)
\( \frac{3 \times 2 \times 1}{2 \times 1} \)
\( \frac{3}{1} \)
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