| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.70 |
| Score | 0% | 74% |
4! = ?
5 x 4 x 3 x 2 x 1 |
|
4 x 3 |
|
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.
What is the distance in miles of a trip that takes 3 hours at an average speed of 15 miles per hour?
| 45 miles | |
| 40 miles | |
| 420 miles | |
| 120 miles |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for distance:
distance = \( \text{speed} \times \text{time} \)
distance = \( 15mph \times 3h \)
45 miles
Alex loaned Christine $1,000 at an annual interest rate of 7%. If no payments are made, what is the total amount owed at the end of the first year?
| $1,070 | |
| $1,080 | |
| $1,050 | |
| $1,090 |
The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:
interest = annual interest rate x loan amount
i = (\( \frac{6}{100} \)) x $1,000
i = 0.07 x $1,000
No payments were made so the total amount due is the original amount + the accumulated interest:
total = $1,000 + $70Convert x-5 to remove the negative exponent.
| \( \frac{-5}{x} \) | |
| \( \frac{1}{x^5} \) | |
| \( \frac{5}{x} \) | |
| \( \frac{-1}{-5x^{5}} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.
What is \( \frac{5}{2} \) - \( \frac{8}{6} \)?
| \( \frac{2}{6} \) | |
| 1\(\frac{1}{6}\) | |
| \( \frac{1}{6} \) | |
| 1 \( \frac{1}{6} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 2 are [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] and the first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60]. The first few multiples they share are [6, 12, 18, 24, 30] making 6 the smallest multiple 2 and 6 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{5 x 3}{2 x 3} \) - \( \frac{8 x 1}{6 x 1} \)
\( \frac{15}{6} \) - \( \frac{8}{6} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{15 - 8}{6} \) = \( \frac{7}{6} \) = 1\(\frac{1}{6}\)