Correct Answer: B

Rationale: To find the number that 6 is equal to 15% of, we set up the equation 0.15x = 6, where x is the unknown number. To solve for x, we divide 6 by 0.15, which gives us x = 40. Therefore, 6 is equal to 15% of the number 40. Choice A (0.9) is incorrect as it is not the result of dividing 6 by 0.15. Choices C (80) and D (90) are incorrect as they do not satisfy the equation 0.15x = 6.

Correct Answer: B

Rationale: Rationale: - If the hand sanitizer contains 70% alcohol, it means that 70% of the 5ml used is pure alcohol. - To find the amount of pure alcohol present, we calculate 70% of 5ml: 0.7 * 5ml = 3.5ml. - Therefore, when 5ml of sanitizer are used, there are 3.5ml of pure alcohol present.

Correct Answer: B

Rationale: The Hindu-Arabic numeral system consists of ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. These ten digits are used as the fundamental symbols to represent numbers in this numerical system. Choice A, 'Two,' is incorrect as there are more than two digits in the system. Choice C, 'Twelve,' is incorrect as it exceeds the total number of digits in the system. Choice D, 'Twenty,' is incorrect as it overestimates the number of digits present in the Hindu-Arabic numeral system.

Correct Answer: A

Rationale: To find 40% of 150, you multiply 150 by 0.40 (which represents 40% in decimal form). This calculation results in 60. Therefore, choice A, 60, is the correct answer. Choice B (65), choice C (70), and choice D (85) are incorrect as they do not reflect the accurate calculation for finding 40% of 150.

Correct Answer: C

Rationale: The absolute value of a number is its distance from zero on the number line, regardless of its sign. In this case, the absolute value of -7 is 7 because it is 7 units away from zero in the negative direction. Therefore, the absolute value of -7 is 7. Choice A (49) is incorrect as it is the square of -7, not the absolute value. Choice B (17) and Choice D (14) are incorrect values and do not represent the absolute value of -7.