| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.59 |
| Score | 0% | 72% |
If a car travels 120 miles in 2 hours, what is the average speed?
| 40 mph | |
| 60 mph | |
| 30 mph | |
| 20 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Which of the following is a mixed number?
\({7 \over 5} \) |
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\(1 {2 \over 5} \) |
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\({5 \over 7} \) |
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\({a \over 5} \) |
A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.
What is \( \sqrt{\frac{25}{16}} \)?
| 1\(\frac{1}{2}\) | |
| 2 | |
| 4 | |
| 1\(\frac{1}{4}\) |
To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:
\( \sqrt{\frac{25}{16}} \)
\( \frac{\sqrt{25}}{\sqrt{16}} \)
\( \frac{\sqrt{5^2}}{\sqrt{4^2}} \)
\( \frac{5}{4} \)
1\(\frac{1}{4}\)
What is \( \frac{8}{6} \) - \( \frac{8}{8} \)?
| 1 \( \frac{2}{24} \) | |
| \( \frac{3}{9} \) | |
| \(\frac{1}{3}\) | |
| \( \frac{5}{10} \) |
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 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80]. The first few multiples they share are [24, 48, 72, 96] making 24 the smallest multiple 6 and 8 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{8 x 4}{6 x 4} \) - \( \frac{8 x 3}{8 x 3} \)
\( \frac{32}{24} \) - \( \frac{24}{24} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{32 - 24}{24} \) = \( \frac{8}{24} \) = \(\frac{1}{3}\)
This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
commutative |
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associative |
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distributive |
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PEDMAS |
The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.