| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.49 |
| Score | 0% | 70% |
What is \( \frac{5}{4} \) - \( \frac{3}{10} \)?
| \( \frac{6}{10} \) | |
| \(\frac{19}{20}\) | |
| 1 \( \frac{7}{20} \) | |
| \( \frac{9}{14} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [20, 40, 60, 80] making 20 the smallest multiple 4 and 10 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{5 x 5}{4 x 5} \) - \( \frac{3 x 2}{10 x 2} \)
\( \frac{25}{20} \) - \( \frac{6}{20} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{25 - 6}{20} \) = \( \frac{19}{20} \) = \(\frac{19}{20}\)
a(b + c) = ab + ac defines which of the following?
commutative property for multiplication |
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distributive property for multiplication |
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commutative property for division |
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distributive property for division |
The distributive property for multiplication helps in solving expressions like a(b + c). It specifies that the result of multiplying one number by the sum or difference of two numbers can be obtained by multiplying each number individually and then totaling the results: a(b + c) = ab + ac. For example, 4(10-5) = (4 x 10) - (4 x 5) = 40 - 20 = 20.
The total water usage for a city is 10,000 gallons each day. Of that total, 30% is for personal use and 57% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 6,300 | |
| 1,100 | |
| 2,700 | |
| 5,200 |
57% of the water consumption is industrial use and 30% is personal use so (57% - 30%) = 27% more water is used for industrial purposes. 10,000 gallons are consumed daily so industry consumes \( \frac{27}{100} \) x 10,000 gallons = 2,700 gallons.
How many hours does it take a car to travel 75 miles at an average speed of 75 miles per hour?
| 9 hours | |
| 8 hours | |
| 3 hours | |
| 1 hour |
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 = \( \frac{75mi}{75mph} \)
1 hour
What is \( \sqrt{\frac{16}{25}} \)?
| \(\frac{3}{7}\) | |
| 3\(\frac{1}{2}\) | |
| \(\frac{4}{5}\) | |
| 3 |
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:
\( \sqrt{\frac{16}{25}} \)
\( \frac{\sqrt{16}}{\sqrt{25}} \)
\( \frac{\sqrt{4^2}}{\sqrt{5^2}} \)
\(\frac{4}{5}\)