| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
Which of the following statements about exponents is false?
b0 = 1 |
|
b1 = 1 |
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all of these are false |
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b1 = b |
A number with an exponent (be) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b1 = b) and a base with an exponent of 0 equals 1 ( (b0 = 1).
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
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a = 7 or a = -7 |
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none of these is correct |
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a = 7 |
The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).
A triathlon course includes a 400m swim, a 30.4km bike ride, and a 3.6km run. What is the total length of the race course?
| 34.4km | |
| 41.3km | |
| 67.9km | |
| 25.7km |
To add these distances, they must share the same unit so first you need to first convert the swim distance from meters (m) to kilometers (km) before adding it to the bike and run distances which are already in km. To convert 400 meters to kilometers, divide the distance by 1000 to get 0.4km then add the remaining distances:
total distance = swim + bike + run
total distance = 0.4km + 30.4km + 3.6km
total distance = 34.4km
How many hours does it take a car to travel 280 miles at an average speed of 40 miles per hour?
| 3 hours | |
| 6 hours | |
| 7 hours | |
| 9 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 = \( \frac{280mi}{40mph} \)
7 hours
The total water usage for a city is 45,000 gallons each day. Of that total, 28% is for personal use and 62% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 7,500 | |
| 3,400 | |
| 15,300 | |
| 2,500 |
62% of the water consumption is industrial use and 28% is personal use so (62% - 28%) = 34% more water is used for industrial purposes. 45,000 gallons are consumed daily so industry consumes \( \frac{34}{100} \) x 45,000 gallons = 15,300 gallons.