| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.46 |
| Score | 0% | 69% |
If a rectangle is twice as long as it is wide and has a perimeter of 6 meters, what is the area of the rectangle?
| 162 m2 | |
| 72 m2 | |
| 98 m2 | |
| 2 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 6 meters so the equation becomes: 2w + 2h = 6.
Putting these two equations together and solving for width (w):
2w + 2h = 6
w + h = \( \frac{6}{2} \)
w + h = 3
w = 3 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 3 - 2w
3w = 3
w = \( \frac{3}{3} \)
w = 1
Since h = 2w that makes h = (2 x 1) = 2 and the area = h x w = 1 x 2 = 2 m2
If a car travels 25 miles in 1 hour, what is the average speed?
| 25 mph | |
| 60 mph | |
| 75 mph | |
| 15 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)What is \( \frac{15\sqrt{32}}{3\sqrt{8}} \)?
| 5 \( \sqrt{4} \) | |
| \(\frac{1}{4}\) \( \sqrt{5} \) | |
| 5 \( \sqrt{\frac{1}{4}} \) | |
| \(\frac{1}{5}\) \( \sqrt{4} \) |
To divide terms with radicals, divide the coefficients and radicands separately:
\( \frac{15\sqrt{32}}{3\sqrt{8}} \)
\( \frac{15}{3} \) \( \sqrt{\frac{32}{8}} \)
5 \( \sqrt{4} \)
What is -2c6 x c3?
| -c6 | |
| -2c-3 | |
| -2c9 | |
| -2c6 |
To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:
-2c6 x c3
(-2 x 1)c(6 + 3)
-2c9
What is \( \frac{2}{8} \) ÷ \( \frac{1}{8} \)?
| \(\frac{3}{40}\) | |
| 2 | |
| \(\frac{16}{63}\) | |
| \(\frac{1}{21}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{2}{8} \) ÷ \( \frac{1}{8} \) = \( \frac{2}{8} \) x \( \frac{8}{1} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{2}{8} \) x \( \frac{8}{1} \) = \( \frac{2 x 8}{8 x 1} \) = \( \frac{16}{8} \) = 2