If Jolene averages 5 miles for every 30 minutes of biking, how far will she bike in 2 hours?

Correct Answer: C

Rationale: If Jolene bikes 5 miles for every 30 minutes, it means she bikes 10 miles in one hour (twice the 30-minute interval). Therefore, in 2 hours, she will cover double the distance she bikes in one hour, which equals 20 miles (10 miles per hour x 2 hours = 20 miles). This makes Choice C, '20 miles,' the correct answer. Choices A, B, and D are incorrect as they do not account for the correct doubling of the hourly distance when calculating the total distance biked in 2 hours.

Correct Answer: B

Rationale: The Roman numeral MMXV represents the year 2015. In Roman numerals, M represents 1000, X represents 10, and V represents 5. Therefore, by converting the Roman numeral MMXV into its numerical equivalent (1000 + 10 + 5), it corresponds to the year 2015. Choice A (2001) is incorrect as it would be represented as MM + I, choice C (2051) would be represented as MM + LI, and choice D (2105) would be represented as MMCV in Roman numerals, making them all inaccurate representations of MMXV.

Correct Answer: D

Rationale: To find the product of 15 and 14, you multiply the two numbers together. 15 multiplied by 14 equals 210. When written in decimal form, it is 2.1. Therefore, the correct answer is 2.1, which corresponds to option D. Choices A, B, and C are incorrect as they reflect values much smaller than the actual product of 15 and 14, which is 210, equivalent to 2.1 in decimal form.

Correct Answer: D

Rationale: To find the product of 32 and 5, you simply multiply the two numbers: 32 5 = 160. Therefore, when expressed in decimal form, the answer is 1.6. Choices A, B, and C are incorrect as they do not represent the correct multiplication result in decimal form. Choice A is way too small, choice B is also too small, and choice C is close but still not the correct result.

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.