| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.07 |
| Score | 0% | 61% |
If a rectangle is twice as long as it is wide and has a perimeter of 30 meters, what is the area of the rectangle?
| 72 m2 | |
| 32 m2 | |
| 50 m2 | |
| 128 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 30 meters so the equation becomes: 2w + 2h = 30.
Putting these two equations together and solving for width (w):
2w + 2h = 30
w + h = \( \frac{30}{2} \)
w + h = 15
w = 15 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 15 - 2w
3w = 15
w = \( \frac{15}{3} \)
w = 5
Since h = 2w that makes h = (2 x 5) = 10 and the area = h x w = 5 x 10 = 50 m2
Simplify \( \sqrt{32} \)
| 3\( \sqrt{4} \) | |
| 4\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) | |
| 2\( \sqrt{2} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{32} \)
\( \sqrt{16 \times 2} \)
\( \sqrt{4^2 \times 2} \)
4\( \sqrt{2} \)
The __________ is the smallest positive integer that is a multiple of two or more integers.
absolute value |
|
greatest common factor |
|
least common factor |
|
least common multiple |
The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.
What is \( \frac{4}{2} \) - \( \frac{3}{4} \)?
| \( \frac{1}{4} \) | |
| 1\(\frac{1}{4}\) | |
| 1 \( \frac{6}{11} \) | |
| 1 \( \frac{9}{18} \) |
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 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40]. The first few multiples they share are [4, 8, 12, 16, 20] making 4 the smallest multiple 2 and 4 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{4 x 2}{2 x 2} \) - \( \frac{3 x 1}{4 x 1} \)
\( \frac{8}{4} \) - \( \frac{3}{4} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{8 - 3}{4} \) = \( \frac{5}{4} \) = 1\(\frac{1}{4}\)
How many 14-passenger vans will it take to drive all 56 members of the football team to an away game?
| 5 vans | |
| 8 vans | |
| 4 vans | |
| 6 vans |
Calculate the number of vans needed by dividing the number of people that need transported by the capacity of one van:
vans = \( \frac{56}{14} \) = 4