| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Find the average of the following numbers: 14, 10, 16, 8.
| 9 | |
| 16 | |
| 7 | |
| 12 |
To find the average of these 4 numbers add them together then divide by 4:
\( \frac{14 + 10 + 16 + 8}{4} \) = \( \frac{48}{4} \) = 12
A triathlon course includes a 400m swim, a 50.1km bike ride, and a 13.4km run. What is the total length of the race course?
| 40.8km | |
| 63.9km | |
| 64.6km | |
| 33.7km |
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 + 50.1km + 13.4km
total distance = 63.9km
The total water usage for a city is 45,000 gallons each day. Of that total, 27% is for personal use and 56% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 15,500 | |
| 13,600 | |
| 6,300 | |
| 13,050 |
56% of the water consumption is industrial use and 27% is personal use so (56% - 27%) = 29% more water is used for industrial purposes. 45,000 gallons are consumed daily so industry consumes \( \frac{29}{100} \) x 45,000 gallons = 13,050 gallons.
A machine in a factory has an error rate of 2 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 3 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 91 | |
| 108.3 | |
| 86.4 | |
| 205.8 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{2}{100} \) x 10 = \( \frac{2 \times 10}{100} \) = \( \frac{20}{100} \) = 0.2 errors per hour
So, in an average hour, the machine will produce 10 - 0.2 = 9.8 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 9.8 = 205.8 error free parts were produced yesterday.
Which of the following is an improper fraction?
\({a \over 5} \) |
|
\({7 \over 5} \) |
|
\(1 {2 \over 5} \) |
|
\({2 \over 5} \) |
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.