| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.32 |
| Score | 0% | 66% |
In a class of 27 students, 14 are taking German and 6 are taking Spanish. Of the students studying German or Spanish, 2 are taking both courses. How many students are not enrolled in either course?
| 11 | |
| 9 | |
| 18 | |
| 24 |
The number of students taking German or Spanish is 14 + 6 = 20. Of that group of 20, 2 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 20 - 2 = 18 who are taking at least one language. 27 - 18 = 9 students who are not taking either language.
What is \( \frac{9}{3} \) - \( \frac{3}{7} \)?
| 2\(\frac{4}{7}\) | |
| 1 \( \frac{8}{14} \) | |
| 2 \( \frac{1}{6} \) | |
| 2 \( \frac{3}{8} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 3 are [3, 6, 9, 12, 15, 18, 21, 24, 27, 30] and the first few multiples of 7 are [7, 14, 21, 28, 35, 42, 49, 56, 63, 70]. The first few multiples they share are [21, 42, 63, 84] making 21 the smallest multiple 3 and 7 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{9 x 7}{3 x 7} \) - \( \frac{3 x 3}{7 x 3} \)
\( \frac{63}{21} \) - \( \frac{9}{21} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{63 - 9}{21} \) = \( \frac{54}{21} \) = 2\(\frac{4}{7}\)
4! = ?
4 x 3 |
|
5 x 4 x 3 x 2 x 1 |
|
4 x 3 x 2 x 1 |
|
3 x 2 x 1 |
A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.
A bread recipe calls for 3 cups of flour. If you only have 1\(\frac{1}{2}\) cups, how much more flour is needed?
| 1 cups | |
| 1\(\frac{1}{4}\) cups | |
| 2\(\frac{1}{2}\) cups | |
| 1\(\frac{1}{2}\) cups |
The amount of flour you need is (3 - 1\(\frac{1}{2}\)) cups. Rewrite the quantities so they share a common denominator and subtract:
(\( \frac{24}{8} \) - \( \frac{12}{8} \)) cups
\( \frac{12}{8} \) cups
1\(\frac{1}{2}\) cups
What is \( \frac{7x^8}{3x^4} \)?
| 2\(\frac{1}{3}\)x32 | |
| 2\(\frac{1}{3}\)x4 | |
| 2\(\frac{1}{3}\)x\(\frac{1}{2}\) | |
| \(\frac{3}{7}\)x4 |
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:
\( \frac{7x^8}{3x^4} \)
\( \frac{7}{3} \) x(8 - 4)
2\(\frac{1}{3}\)x4