| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.02 |
| Score | 0% | 60% |
What is \( \frac{7}{3} \) + \( \frac{4}{11} \)?
| 1 \( \frac{8}{14} \) | |
| 2 \( \frac{9}{33} \) | |
| \( \frac{6}{33} \) | |
| 2\(\frac{23}{33}\) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 3 are [3, 6, 9, 12, 15, 18, 21, 24, 27, 30] and the first few multiples of 11 are [11, 22, 33, 44, 55, 66, 77, 88, 99]. The first few multiples they share are [33, 66, 99] making 33 the smallest multiple 3 and 11 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{7 x 11}{3 x 11} \) + \( \frac{4 x 3}{11 x 3} \)
\( \frac{77}{33} \) + \( \frac{12}{33} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{77 + 12}{33} \) = \( \frac{89}{33} \) = 2\(\frac{23}{33}\)
Which of these numbers is a factor of 36?
| 9 | |
| 37 | |
| 35 | |
| 11 |
The factors of a number are all positive integers that divide evenly into the number. The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36.
A machine in a factory has an error rate of 6 parts per 100. The machine normally runs 24 hours a day and produces 9 parts per hour. Yesterday the machine was shut down for 7 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 143.8 | |
| 107.2 | |
| 114.2 | |
| 103.7 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{6}{100} \) x 9 = \( \frac{6 \times 9}{100} \) = \( \frac{54}{100} \) = 0.54 errors per hour
So, in an average hour, the machine will produce 9 - 0.54 = 8.46 error free parts.
The machine ran for 24 - 7 = 17 hours yesterday so you would expect that 17 x 8.46 = 143.8 error free parts were produced yesterday.
Which of the following statements about exponents is false?
b1 = b |
|
b1 = 1 |
|
all of these are false |
|
b0 = 1 |
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).
Which of the following is not an integer?
0 |
|
1 |
|
-1 |
|
\({1 \over 2}\) |
An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.