What must you always use in all math?
- A. PEMDAS
- B. Variables
- C. Conversion factors
- D. Estimation
Correct Answer: A
Rationale: The correct answer is A: PEMDAS. PEMDAS stands for the order of operations: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). It is a fundamental rule to follow in mathematics to ensure calculations are done correctly. Choices B, C, and D are incorrect as they do not encompass the essential rule that PEMDAS provides for solving mathematical expressions.
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What is the probability of consecutively pulling two more orange blocks, without replacement, from a bag containing 3 orange blocks, 5 green blocks, and 4 purple blocks?
- A. 3/12
- B. 3/55
- C. 2/10
- D. 1/3
Correct Answer: B
Rationale: To calculate the probability of consecutively pulling two more orange blocks without replacement, we first determine the probability of pulling an orange block on the first draw, which is 3/12 (3 orange blocks out of 12 total blocks). After removing one orange block, there are only 11 blocks left, so the probability of pulling another orange block on the second draw is 2/11. To find the combined probability, we multiply the probabilities together: (3/12) * (2/11) = 6/132 = 3/55. Therefore, the correct answer is B. Choice A (3/12) incorrectly simplifies the probability before calculating the second draw. Choice C (2/10) does not consider the specific number of orange blocks in the bag. Choice D (1/3) does not account for the reduced number of blocks after the first draw.
A woman wants to stack two bookcases, one 32.75 inches tall and another 17.25 inches tall. How tall will they be when stacked together?
- A. 49.5 inches
- B. 50 inches
- C. 48 inches
- D. 51 inches
Correct Answer: B
Rationale: To find the total height of the stacked bookcases, you need to add the heights of the two bookcases: 32.75 inches + 17.25 inches = 50 inches. Therefore, the correct answer is 50 inches. Choice A (49.5 inches) is incorrect as it does not consider rounding off the total height. Choices C (48 inches) and D (51 inches) are incorrect as they do not accurately calculate the sum of the heights of the two bookcases.
Arrange the following fractions from least to greatest: 2/3, 1/2, 5/8, 7/9.
- A. 7/9, 5/8, 2/3, 1/2
- B. 1/2, 2/3, 5/8, 7/9
- C. 1/2, 5/8, 2/3, 7/9
- D. 7/9, 2/3, 5/8, 1/2
Correct Answer: C
Rationale: To compare the fractions, it is beneficial to convert them to decimals or find a common denominator. When converted to decimals: 1/2 = 0.50, 5/8 = 0.625, 2/3 ≈ 0.666, and 7/9 ≈ 0.778. Therefore, the correct order from least to greatest is 1/2, 5/8, 2/3, 7/9. Choice A is incorrect because it places 7/9 first, which is the greatest fraction. Choice B is incorrect as it incorrectly lists the fractions. Choice D is incorrect as it starts with 7/9, which is the largest fraction instead of the smallest.
When is a histogram preferred over a bar graph?
- A. Comparison between categories
- B. Frequency
- C. Percentages
- D. Proportions
Correct Answer: B
Rationale: Histograms are specifically designed to display the frequency distribution of continuous data, showing the distribution of values over intervals or bins. On the other hand, bar graphs are used to compare different categories or discrete data points. Therefore, the correct answer is B. Choices A, C, and D are incorrect because histograms are not primarily used for comparing categories, percentages, or proportions, but rather for visualizing the distribution of frequencies within data intervals.
During week 1, Cameron worked 5 shifts. During week 2, she worked twice as many shifts. During week 3, she added 4 more shifts. How many shifts did Cameron work in week 3?
- A. 15 shifts
- B. 14 shifts
- C. 16 shifts
- D. 17 shifts
Correct Answer: B
Rationale: To find out how many shifts Cameron worked in week 3, we first determine the shifts worked in weeks 1 and 2. In week 1, Cameron worked 5 shifts. In week 2, she worked twice as many shifts, which is 5 x 2 = 10 shifts. Adding the 4 more shifts in week 3, the total shifts worked in week 3 would be 5 (week 1) + 10 (week 2) + 4 (week 3) = 19 shifts. Therefore, the correct answer is 14 shifts (Option B), not 15 shifts (Option A), 16 shifts (Option C), or 17 shifts (Option D).