| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
Simplify \( \sqrt{32} \)
| 6\( \sqrt{4} \) | |
| 4\( \sqrt{2} \) | |
| 9\( \sqrt{2} \) | |
| 2\( \sqrt{4} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{32} \)
\( \sqrt{16 \times 2} \)
\( \sqrt{4^2 \times 2} \)
4\( \sqrt{2} \)
If a rectangle is twice as long as it is wide and has a perimeter of 42 meters, what is the area of the rectangle?
| 98 m2 | |
| 128 m2 | |
| 72 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 42 meters so the equation becomes: 2w + 2h = 42.
Putting these two equations together and solving for width (w):
2w + 2h = 42
w + h = \( \frac{42}{2} \)
w + h = 21
w = 21 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 21 - 2w
3w = 21
w = \( \frac{21}{3} \)
w = 7
Since h = 2w that makes h = (2 x 7) = 14 and the area = h x w = 7 x 14 = 98 m2
A machine in a factory has an error rate of 6 parts per 100. The machine normally runs 24 hours a day and produces 5 parts per hour. Yesterday the machine was shut down for 8 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 121.4 | |
| 141.4 | |
| 107.8 | |
| 75.2 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{6}{100} \) x 5 = \( \frac{6 \times 5}{100} \) = \( \frac{30}{100} \) = 0.3 errors per hour
So, in an average hour, the machine will produce 5 - 0.3 = 4.7 error free parts.
The machine ran for 24 - 8 = 16 hours yesterday so you would expect that 16 x 4.7 = 75.2 error free parts were produced yesterday.
What is \( \frac{9\sqrt{15}}{3\sqrt{5}} \)?
| \(\frac{1}{3}\) \( \sqrt{3} \) | |
| \(\frac{1}{3}\) \( \sqrt{\frac{1}{3}} \) | |
| 3 \( \sqrt{3} \) | |
| 3 \( \sqrt{\frac{1}{3}} \) |
To divide terms with radicals, divide the coefficients and radicands separately:
\( \frac{9\sqrt{15}}{3\sqrt{5}} \)
\( \frac{9}{3} \) \( \sqrt{\frac{15}{5}} \)
3 \( \sqrt{3} \)
What is the next number in this sequence: 1, 7, 13, 19, 25, __________ ?
| 38 | |
| 39 | |
| 31 | |
| 26 |
The equation for this sequence is:
an = an-1 + 6
where n is the term's order in the sequence, an is the value of the term, and an-1 is the value of the term before an. This makes the next number:
a6 = a5 + 6
a6 = 25 + 6
a6 = 31