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.
You may also like to solve these questions
What is the formula to find the circumference of a circle?
- A. Circumference = 2πr
- B. Circumference = πr²
- C. Circumference = 2r²
- D. Circumference = r²π
Correct Answer: A
Rationale: The correct formula to find the circumference of a circle is C = 2πr, where C represents the circumference and r is the radius of the circle. Choice B, Circumference = πr², represents the formula for the area of a circle rather than the circumference. Choice C, Circumference = 2r², is incorrect as it does not involve π in the formula. Choice D, Circumference = r²π, has the terms reversed compared to the correct formula; the formula should start with the constant (2) multiplied by π, followed by the radius.
What percentage of the total rainfall in this timeframe occurs during October?
- A. 0.135
- B. 0.151
- C. 0.169
- D. 0.177
Correct Answer: B
Rationale: To calculate the percentage of rainfall that occurs during October, divide October's rainfall (4.5 inches) by the total rainfall (29.38 inches) and multiply by 100. So, (4.5 / 29.38) * 100 = 15.31%. Among the choices given, option B, 0.151, is the closest to this calculated percentage. Options A, C, and D are not correct as they do not match the accurate calculation based on the provided data.
What is the equation that describes the relationship between x and y in the table below: x = 2, y = 6; x = 3, y = 9; x = 4, y = 12?
- A. y = 3x
- B. x = 3y
- C. y = x/3
- D. y = x + 3
Correct Answer: A
Rationale: The correct answer is y = 3x. By examining the table provided, we can see that for each increase of 1 in x, y increases by 3. This consistent pattern indicates that y is three times the value of x, leading to the equation y = 3x. Choices B, C, and D do not match the pattern observed in the table and are therefore incorrect.
Which is larger, feet or meters? What is the correct conversion factor between feet and meters?
- A. Feet are larger; 1 foot is 0.3048 meters
- B. Meters are larger; 1 meter is 3.28 feet
- C. Feet are smaller; 1 foot is 0.5 meters
- D. Meters are smaller; 1 meter is 2 feet
Correct Answer: A
Rationale: The correct answer is A. Feet are larger than meters. The conversion factor between feet and meters is 1 foot = 0.3048 meters. Choice B is incorrect as it states that meters are larger than feet, which is the opposite of the truth. Choice C is incorrect as it provides an incorrect conversion factor of 1 foot = 0.5 meters, which is inaccurate. Choice D is also incorrect as it suggests that meters are smaller than feet, which is not true.
A patient requires a 30% decrease in the dosage of their medication. Their current dosage is 340 mg. What will their dosage be after the decrease?
- A. 70 mg
- B. 238 mg
- C. 270 mg
- D. 340 mg
Correct Answer: B
Rationale: To calculate a 30% decrease in 340 mg, you multiply 340 by 0.3, which equals 102 mg. Subtracting this from the current dosage gives 340 - 102 = 238 mg. Therefore, the correct answer is 238 mg. Choice A (70 mg) is incorrect because it represents a 70% decrease, not 30%. Choice C (270 mg) is incorrect as it does not reflect the correct calculation for a 30% decrease. Choice D (340 mg) is the initial dosage and not the reduced dosage after a 30% decrease.
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