Convert this military time to regular time: 2120 hours.

Correct Answer: B

Rationale: To convert military time to regular time, subtract 12 from the hours if the time is in the afternoon or evening. In this case, 21 - 12 = 9, so 2120 hours is equivalent to 9:20 P.M. Therefore, the correct answer is option B, 9:20 P.M. Choices A, C, and D are incorrect because they do not correctly adjust the military time to regular time format. Choice A shows 9:20 A.M., which is incorrect as the time is in the evening. Choices C and D show times that are not derived from the given military time, making them incorrect as well.

Correct Answer: D

Rationale: The surface area of a cube is calculated using the formula: 6 * (side length)^2. Substituting the side length of 5cm into the formula, we get: 6 * (5cm)^2 = 6 * 25cm^2 = 150 sq cm. Therefore, the total surface area of the toy block is 150 sq cm. Choices A (25 sq cm), B (50 sq cm), and C (125 sq cm) are incorrect as they do not correctly calculate the total surface area of the cube.

Correct Answer: B

Rationale: When the real shed roof measures 4 feet by 5 feet, on a 1:10 scale plan, the measurements on the plan would be 1/10 of the real measurements. Therefore, the correct answer is 40 inches by 50 inches since it represents 1/10 of 4 feet by 5 feet. Choice A (80 inches by 100 inches) is incorrect because it is equivalent to the real shed measurements, not the scaled plan. Choice C (4.8 inches by 6 inches) is incorrect as it does not reflect the 1:10 scale reduction. Choice D (4 inches by 5 inches) is incorrect because it does not consider the scale factor of 1:10.

Correct Answer: C

Rationale: To convert miles to kilometers, you can use the conversion factor of 1 mile is equal to 1.609 kilometers. Therefore, to find the number of kilometers in 12 miles, you can multiply 12 miles by 1.609 to get 19.2 kilometers. The correct answer is 19.2 kilometers, making choice C the correct option. Choice A (7.5 kilometers) is incorrect because it represents half the correct conversion. Choice B (13.2 kilometers) is incorrect as it does not apply the correct conversion factor. Choice D (22 kilometers) is incorrect and represents an incorrect conversion calculation.

Correct Answer: A

Rationale: To find 15% of 95, you multiply 95 by 0.15 (which represents 15% as a decimal). Therefore, 95 * 0.15 = 14.25. The correct answer is A. Choice B, 18.5, is incorrect as it does not represent 15% of 95. Choices C and D, 24.25 and 28.5, are also incorrect calculations for 15% of 95.

Correct Answer: D

Rationale: When you multiply 2 by 5, the result is 10, not 13. Therefore, the correct answer is 10, which is option D. Choices A, B, and C are incorrect because they do not represent the correct product of multiplying 2 by 5.

Correct Answer: B

Rationale: Rationale: - Relatively prime numbers are numbers that share no common factors other than 1. - To determine if two numbers are relatively prime, we need to find the greatest common divisor (GCD) of the two numbers. If the GCD is 1, then the numbers are relatively prime. - Let's calculate the GCD for each pair of numbers: A) GCD(12, 16) = 4, not relatively prime B) GCD(15, 17) = 1, relatively prime C) GCD(20, 24) = 4, not relatively prime D) GCD(28, 36) = 4, not relatively prime Therefore, the pair of numbers 15 and 17 are relatively prime because their greatest common divisor is 1, meaning they share no common factors other than 1.

Correct Answer: B

Rationale: The total number of marbles in the bag is 5 (red) + 7 (blue) = 12 marbles. The probability of drawing a red marble is the number of red marbles divided by the total number of marbles: 5/12. Simplifying 5/12 gives 1/3. Therefore, the correct probability of drawing a red marble is 1/3. Choice A (1/4) is incorrect because there are more red marbles than 1/4 of the total marbles. Choice C (1/2) is incorrect as it represents half of the total marbles. Choice D (2/3) is incorrect as it implies there are more red marbles than there actually are.

Correct Answer: C

Rationale: To simplify the expression -5 - (-6), we can rewrite it as -5 + 6 (since subtracting a negative number is equivalent to adding its positive counterpart). This gives us -5 + 6 = 1. Therefore, the correct answer is 1. Choice A, ½, is incorrect because the subtraction of a negative number results in a positive number. Choices B and D are also incorrect as they do not match the simplified result of -5 - (-6), which is 1.