Correct Answer: A

Rationale: The correct equation that models the relationship between x and y when y is three times x is y = 3x. This equation represents that y is equal to three times x. Choice B (x = 3y) incorrectly reverses the relationship, stating that x is equal to three times y. Choice C (y = x + 3) and Choice D (y = x / 3) do not correctly represent a relationship where y is three times x, making them incorrect choices.

Correct Answer: A

Rationale: Group Alpha has the largest number of patients because it represents 1/2 of the total population, which is the highest fraction among the groups. Group Beta represents 1/3 of the population, and Group Gamma represents 1/6 of the population, making them smaller fractions in comparison. Group Delta is not mentioned in the question and is therefore unrelated to the comparison of the groups.

Correct Answer: C

Rationale: The smallest group is Group Gamma, which had 1/6 of the total number of patients. To determine the smallest group, compare the fractions representing the portions of patients in each group. 1/6 is smaller than 1/3 and 1/2, making Group Gamma the smallest. Group Alpha and Group Beta have larger fractions of patients, making them larger groups compared to Group Gamma.

Correct Answer: C

Rationale: To determine the order from smallest to largest groups, we look at the fractions representing the groups. Group Gamma has 1/6, which is the smallest fraction, followed by Group Alpha with 1/2, and Group Beta with 1/3 being the largest fraction. So, the correct order is Gamma, Alpha, Beta. Choice A is incorrect because it lists Alpha, Beta, Gamma, which is the reverse order. Choice B is incorrect as it lists Alpha, Gamma, Beta, which is also incorrect. Choice D is incorrect as it lists Gamma, Beta, Alpha, which is not the correct order based on the fractions provided.

Correct Answer: A

Rationale: To find the time needed to travel 180 miles at the same speed of 60 miles per hour, you divide the total distance by the speed. 180 miles · 60 mph = 3 hours. Therefore, it will take 3 hours to travel 180 miles at the given speed. Choice B, 4 hours, is incorrect as it does not align with the calculation. Choice C, 2.5 hours, is incorrect as it underestimates the time needed for the distance. Choice D, 5 hours, is incorrect as it overestimates the time required based on the given speed.