| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.15 |
| Score | 0% | 63% |
Cooks are needed to prepare for a large party. Each cook can bake either 2 large cakes or 18 small cakes per hour. The kitchen is available for 2 hours and 36 large cakes and 340 small cakes need to be baked.
How many cooks are required to bake the required number of cakes during the time the kitchen is available?
| 15 | |
| 19 | |
| 11 | |
| 8 |
If a single cook can bake 2 large cakes per hour and the kitchen is available for 2 hours, a single cook can bake 2 x 2 = 4 large cakes during that time. 36 large cakes are needed for the party so \( \frac{36}{4} \) = 9 cooks are needed to bake the required number of large cakes.
If a single cook can bake 18 small cakes per hour and the kitchen is available for 2 hours, a single cook can bake 18 x 2 = 36 small cakes during that time. 340 small cakes are needed for the party so \( \frac{340}{36} \) = 9\(\frac{4}{9}\) cooks are needed to bake the required number of small cakes.
Because you can't employ a fractional cook, round the number of cooks needed for each type of cake up to the next whole number resulting in 9 + 10 = 19 cooks.
What is \( \frac{3}{8} \) + \( \frac{5}{10} \)?
| \( \frac{7}{40} \) | |
| \( \frac{4}{40} \) | |
| \( \frac{4}{7} \) | |
| \(\frac{7}{8}\) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [40, 80] making 40 the smallest multiple 8 and 10 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{3 x 5}{8 x 5} \) + \( \frac{5 x 4}{10 x 4} \)
\( \frac{15}{40} \) + \( \frac{20}{40} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{15 + 20}{40} \) = \( \frac{35}{40} \) = \(\frac{7}{8}\)
What is 5a2 x 4a7?
| 20a-5 | |
| 9a7 | |
| 20a9 | |
| 20a14 |
To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:
5a2 x 4a7
(5 x 4)a(2 + 7)
20a9
If a car travels 60 miles in 4 hours, what is the average speed?
| 55 mph | |
| 15 mph | |
| 65 mph | |
| 30 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)The __________ is the smallest positive integer that is a multiple of two or more integers.
absolute value |
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least common factor |
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greatest common factor |
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least common multiple |
The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.