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Cora skated around the rink 27 times but fell 20 times. What percentage of the time did she not fall?
- A. 0.37
- B. 0.74
- C. 0.26
- D. 0.15
Correct Answer: C
Rationale: To find the percentage of the time Cora did not fall, subtract the number of times she fell (20) from the total number of times she skated around the rink (27). This gives us 27 - 20 = 7 times she did not fall. To express this as a percentage, calculate (7/27) * 100% = 25.93%, which is approximately 26%. Therefore, the correct answer is 0.26 (C). Choice A (0.37), Choice B (0.74), and Choice D (0.15) are incorrect as they do not represent the percentage of the time Cora did not fall based on the information provided.
You may also like to solve these questions
How many feet are in a mile?
- A. 1,000 ft
- B. 5,280 ft
- C. 2,000 ft
- D. 10,000 ft
Correct Answer: B
Rationale: The correct answer is B: 5,280 feet in a mile. This is a standard conversion used in the Imperial system of measurement. Choice A, 1,000 ft, is incorrect as it is a common misconception and not the accurate conversion. Choice C, 2,000 ft, is also incorrect. Choice D, 10,000 ft, is significantly higher than the actual conversion and is incorrect. Remember, when converting miles to feet, the accurate value is 5,280 feet in a mile.
Simplify the following expression:
6 + 7 3 - 4 2
- A. -42
- B. -20
- C. 23
- D. 20
Correct Answer: B
Rationale: ollow the order of operations (PEMDAS: Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)):
Multiply: 7 3 = 21, and 4 2 = 8
Perform addition and subtraction: 6 + 21 - 8 = 19
Thus, the simplified expression equals 19.
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.
How many millimeters are in a meter?
- A. 100 mm
- B. 1,000 mm
- C. 10,000 mm
- D. 100,000 mm
Correct Answer: B
Rationale: The correct answer is B: 1,000 mm. This is because there are 1,000 millimeters in a meter. To convert from meters to millimeters, you need to multiply by 1,000. Choices A, C, and D are incorrect. A meter is equivalent to 1,000 millimeters, not 100 (A), 10,000 (C), or 100,000 (D) millimeters.
What is the least common denominator of two fractions?
- A. The smallest number that is a multiple of both denominators
- B. The smallest number that both fractions can divide into evenly
- C. The least common multiple of both denominators
- D. The greatest common factor of both denominators
Correct Answer: C
Rationale: The least common denominator of two fractions is the least common multiple of both denominators. This is because the least common denominator is the smallest number that both denominators can divide into evenly, ensuring that both fractions can be expressed with a common denominator. Choice A is incorrect as the least common denominator is a multiple of both denominators, not a number that multiplies into both. Choice B is incorrect because the common denominator needs to be a multiple of both denominators, not just a number they can divide into evenly. Choice D is incorrect as the greatest common factor is not used to find the least common denominator, but rather the least common multiple.