Correct Answer: C

Rationale: Let r be the number of red cans and b be the number of blue cans. The total cans equation is r + b = 10. The total cost equation is r + 2b = 16. By solving these equations simultaneously, we find r = 4. Therefore, Jessica bought 4 red cans. Choice A, 2 red cans, is incorrect because it does not satisfy the total cans or total cost condition. Choices B and D are also incorrect as they do not fulfill both conditions simultaneously.

Correct Answer: A

Rationale: To find the sum of fractions, add the numerators if the denominators are the same. Here, 3/8 + 5/8 = (3+5)/8 = 8/8 = 1. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not represent the correct sum of the fractions provided in the question.

Correct Answer: D

Rationale: To find the sum of fractions, they need to have a common denominator. In this case, the common denominator is 8. So, 3/4 = 6/8. Adding 6/8 and 5/8 gives 11/8, which simplifies to 1 3/8. Therefore, the correct answer is 1 3/8, which corresponds to choice A. Choices B, C, and D are incorrect as they do not represent the correct sum of 3/4 and 5/8.

Correct Answer: C

Rationale: An equation represents a function if each input (x-value) corresponds to exactly one output (y-value). In the equation x = y^2, for a single x-value, there are two possible y-values (positive and negative square root), violating the definition of a function. This violates the vertical line test, where a vertical line intersects the graph in more than one point for non-functions. Choices A, B, and D all pass the vertical line test and represent functions, making them incorrect answers.

Correct Answer: C

Rationale: To find the sum of all six numbers, we multiply the average (6) by the total numbers (6), which equals 36. Since the sum of five numbers is 25, the sixth number can be found by subtracting the sum of five numbers from the total sum: 36 - 25 = 11. Therefore, the sixth number is 11. Choice A, 8, is incorrect because adding 8 to the sum of five numbers (25) would result in a total greater than the correct sum of all six numbers (36). Choice B, 10, is incorrect because adding 10 to the sum of five numbers (25) would also result in a total greater than the correct sum of all six numbers (36). Choice D, 12, is incorrect because adding 12 to the sum of five numbers (25) would exceed the correct sum of all six numbers (36).