Which of the following equations correctly models the relationship between x and y when y is three times x?
- A. y = 3x
- B. x = 3y
- C. y = x + 3
- D. y = x / 3
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.
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If you have a rectangle with a width of 5 inches and a length of 10 inches and scale it by a factor of 2, what will the new perimeter be?
- A. 30 inches
- B. 40 inches
- C. 60 inches
- D. 50 inches
Correct Answer: C
Rationale: When a rectangle is scaled by a factor of 2, both the length and width are multiplied by 2. The new dimensions become width = 5 * 2 = 10 inches and length = 10 * 2 = 20 inches. Therefore, the new perimeter is calculated as 2 * (10 + 20) = 60 inches. Choice A, B, and D are incorrect as they do not reflect the correct calculation based on scaling the dimensions of the rectangle.
A charter bus driver drove at an average speed of 65 mph for 305 miles. If he stops at a gas station for 15 minutes, then drives another 162 miles at 80 mph, how long will it have been since he began the trip?
- A. 0.96 hours
- B. 6.44 hours
- C. 6.69 hours
- D. 6.97 hours
Correct Answer: C
Rationale: To calculate the total time, first find the time for the first leg of the trip: 305 miles / 65 mph = 4.69 hours. Then, add the time for the second leg: 162 miles / 80 mph = 2.025 hours. Next, add the 15-minute stop in hours (15 minutes = 0.25 hours). Finally, add the times together: 4.69 hours + 2.025 hours + 0.25 hours = 6.965 hours, which rounds to 6.69 hours. Therefore, the correct answer is 6.69 hours. Choice A is incorrect because it does not account for the total driving time correctly. Choice B is incorrect as it does not include the time for the gas station stop. Choice D is wrong as it miscalculates the total time taken for the trip.
Out of 9 trips, a person chooses the longest route for 3 of them. What percentage of their trips is the longest route?
- A. 0.25
- B. 0.33
- C. 0.5
- D. 0.75
Correct Answer: B
Rationale: To find the percentage of trips where the person chose the longest route, divide the number of longest route trips (3) by the total number of trips (9) and multiply by 100. This gives (3/9) * 100 = 33.33%, which can be rounded to 33%. Therefore, the correct answer is B. Choice A (0.25), C (0.5), and D (0.75) are incorrect because they do not accurately represent the percentage of trips where the longest route was chosen based on the given information.
A container holds 10 liters of water. If 25% of the water is used, how many liters are left?
- A. 7.5 liters
- B. 8 liters
- C. 6.5 liters
- D. 8.5 liters
Correct Answer: A
Rationale: To find the amount of water left after 25% is used, you need to calculate 75% of the total water. 75% of 10 liters is 7.5 liters, which means that 7.5 liters of water are left. Therefore, the correct answer is A. Choice B (8 liters) is incorrect because this would be the total water remaining if 20% was used, not 25%. Choice C (6.5 liters) is incorrect as it does not account for the correct percentage of water left. Choice D (8.5 liters) is incorrect as it miscalculates the amount of water remaining after 25% is used.
Veronica has to create the holiday schedule for the neonatal unit at her hospital. She knows that 35% of the staff members will not be available because they are taking vacation days during the holiday. Of the remaining staff members who will be available, only 20% are certified to work in the neonatal unit. What percentage of the total staff is certified and available to work in the neonatal unit during the holiday?
- A. 0.07
- B. 0.13
- C. 0.65
- D. 0.8
Correct Answer: A
Rationale: After 35% of the staff is on vacation, 65% remain. Of these remaining staff, 20% are certified to work in the neonatal unit. To find the percentage of the total staff that is certified and available, we calculate 20% of the 65% remaining staff: 0.2 * 65% = 13%. Therefore, 13% of the total staff is certified and available to work in the neonatal unit during the holiday. The correct answer is 0.13. Choices B, C, and D are incorrect because they do not accurately represent the correct percentage calculation based on the given information.