| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.73 |
| Score | 0% | 55% |
A tiger in a zoo has consumed 70 pounds of food in 10 days. If the tiger continues to eat at the same rate, in how many more days will its total food consumtion be 105 pounds?
| 5 | |
| 7 | |
| 9 | |
| 13 |
If the tiger has consumed 70 pounds of food in 10 days that's \( \frac{70}{10} \) = 7 pounds of food per day. The tiger needs to consume 105 - 70 = 35 more pounds of food to reach 105 pounds total. At 7 pounds of food per day that's \( \frac{35}{7} \) = 5 more days.
A machine in a factory has an error rate of 7 parts per 100. The machine normally runs 24 hours a day and produces 8 parts per hour. Yesterday the machine was shut down for 3 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 156.2 | |
| 81.9 | |
| 125.1 | |
| 131 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 8 = \( \frac{7 \times 8}{100} \) = \( \frac{56}{100} \) = 0.56 errors per hour
So, in an average hour, the machine will produce 8 - 0.56 = 7.4399999999999995 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 7.4399999999999995 = 156.2 error free parts were produced yesterday.
The total water usage for a city is 40,000 gallons each day. Of that total, 11% is for personal use and 26% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 6,000 | |
| 5,600 | |
| 10,500 | |
| 5,100 |
26% of the water consumption is industrial use and 11% is personal use so (26% - 11%) = 15% more water is used for industrial purposes. 40,000 gallons are consumed daily so industry consumes \( \frac{15}{100} \) x 40,000 gallons = 6,000 gallons.
A circular logo is enlarged to fit the lid of a jar. The new diameter is 30% larger than the original. By what percentage has the area of the logo increased?
| 20% | |
| 15% | |
| 17\(\frac{1}{2}\)% | |
| 27\(\frac{1}{2}\)% |
The area of a circle is given by the formula A = πr2 where r is the radius of the circle. The radius of a circle is its diameter divided by two so A = π(\( \frac{d}{2} \))2. If the diameter of the logo increases by 30% the radius (and, consequently, the total area) increases by \( \frac{30\text{%}}{2} \) = 15%
This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
PEDMAS |
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commutative |
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distributive |
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associative |
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.