| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.30 |
| Score | 0% | 66% |
If a rectangle is twice as long as it is wide and has a perimeter of 18 meters, what is the area of the rectangle?
| 18 m2 | |
| 8 m2 | |
| 50 m2 | |
| 72 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 18 meters so the equation becomes: 2w + 2h = 18.
Putting these two equations together and solving for width (w):
2w + 2h = 18
w + h = \( \frac{18}{2} \)
w + h = 9
w = 9 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 9 - 2w
3w = 9
w = \( \frac{9}{3} \)
w = 3
Since h = 2w that makes h = (2 x 3) = 6 and the area = h x w = 3 x 6 = 18 m2
If there were a total of 50 raffle tickets sold and you bought 3 tickets, what's the probability that you'll win the raffle?
| 1% | |
| 6% | |
| 4% | |
| 3% |
You have 3 out of the total of 50 raffle tickets sold so you have a (\( \frac{3}{50} \)) x 100 = \( \frac{3 \times 100}{50} \) = \( \frac{300}{50} \) = 6% chance to win the raffle.
Convert b-2 to remove the negative exponent.
| \( \frac{-2}{b} \) | |
| \( \frac{-1}{-2b^{2}} \) | |
| \( \frac{-1}{b^{-2}} \) | |
| \( \frac{1}{b^2} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.
What is -7x4 - 3x4?
| 10x4 | |
| -4x4 | |
| 10x-4 | |
| -10x4 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:
-7x4 - 3x4
(-7 - 3)x4
-10x4
How many hours does it take a car to travel 225 miles at an average speed of 45 miles per hour?
| 6 hours | |
| 5 hours | |
| 9 hours | |
| 3 hours |
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 time:
time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{225mi}{45mph} \)
5 hours