| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.40 |
| Score | 0% | 68% |
If a rectangle is twice as long as it is wide and has a perimeter of 24 meters, what is the area of the rectangle?
| 32 m2 | |
| 128 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 24 meters so the equation becomes: 2w + 2h = 24.
Putting these two equations together and solving for width (w):
2w + 2h = 24
w + h = \( \frac{24}{2} \)
w + h = 12
w = 12 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 12 - 2w
3w = 12
w = \( \frac{12}{3} \)
w = 4
Since h = 2w that makes h = (2 x 4) = 8 and the area = h x w = 4 x 8 = 32 m2
8 members of a bridal party need transported to a wedding reception but there are only 2 3-passenger taxis available to take them. How many will need to find other transportation?
| 9 | |
| 6 | |
| 8 | |
| 2 |
There are 2 3-passenger taxis available so that's 2 x 3 = 6 total seats. There are 8 people needing transportation leaving 8 - 6 = 2 who will have to find other transportation.
What is \( \frac{1}{7} \) x \( \frac{2}{9} \)?
| \(\frac{2}{63}\) | |
| \(\frac{2}{9}\) | |
| \(\frac{3}{25}\) | |
| \(\frac{8}{63}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{1}{7} \) x \( \frac{2}{9} \) = \( \frac{1 x 2}{7 x 9} \) = \( \frac{2}{63} \) = \(\frac{2}{63}\)
What is \( \frac{5}{6} \) - \( \frac{5}{12} \)?
| \( \frac{8}{12} \) | |
| 2 \( \frac{7}{12} \) | |
| \(\frac{5}{12}\) | |
| 1 \( \frac{9}{17} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [12, 24, 36, 48, 60] making 12 the smallest multiple 6 and 12 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{5 x 2}{6 x 2} \) - \( \frac{5 x 1}{12 x 1} \)
\( \frac{10}{12} \) - \( \frac{5}{12} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{10 - 5}{12} \) = \( \frac{5}{12} \) = \(\frac{5}{12}\)
How many hours does it take a car to travel 75 miles at an average speed of 15 miles per hour?
| 3 hours | |
| 8 hours | |
| 6 hours | |
| 5 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 = \( \frac{75mi}{15mph} \)
5 hours