Jonathan pays a $65 monthly flat rate for his cell phone. He is charged $0.12 per minute for each minute used in a roaming area. Which of the following expressions represents his monthly bill for x roaming minutes?
- A. 65 + 0.12x
- B. 65x + 0.12
- C. 65.12x
- D. 65 + 0.12x
Correct Answer: A
Rationale: The correct expression for Jonathan's monthly bill is 65 + 0.12x, where x represents the number of roaming minutes. The $65 monthly flat rate is added to the product of $0.12 per minute and the number of roaming minutes (x). Choice B is incorrect because it incorrectly multiplies the flat rate by x and adds the per-minute charge. Choice C is incorrect as it combines the flat rate and the per-minute charge into a single value. Choice D is incorrect as it incorrectly multiplies the flat rate by x and adds the per-minute charge separately.
You may also like to solve these questions
Solve for x: 3(x - 1) = 2(3x - 9)
- A. x = 2
- B. x = 8/3
- C. x = -5
- D. x = 5
Correct Answer: D
Rationale: To solve the equation 3(x - 1) = 2(3x - 9), first distribute and simplify both sides to get 3x - 3 = 6x - 18. Next, subtract 3x from both sides to get -3 = 3x - 18. Then, add 18 to both sides to obtain 15 = 3x. Finally, divide by 3 to find x = 5. Therefore, the correct answer is x = 5. Choices A, B, and C are incorrect because they do not represent the correct solution to the given equation after proper algebraic manipulation.
A farmer had about 150 bags of potatoes on his trailer. Each bag contained from 23 to 27 pounds of potatoes. What is the best estimate of the total number of pounds of potatoes on the farmer's trailer?
- A. 3,000 pounds
- B. 3,700 pounds
- C. 4,100 pounds
- D. 5,000 pounds
Correct Answer: B
Rationale: To estimate the total number of pounds of potatoes on the farmer's trailer, we can use the average weight of a bag of potatoes. The average weight is calculated by adding the minimum and maximum weights of the bags and dividing by 2: (23 + 27) / 2 = 25 pounds. Next, multiply the average weight by the total number of bags: 25 pounds/bag * 150 bags = 3,750 pounds. Therefore, the best estimate of the total number of pounds of potatoes on the farmer's trailer is 3,750 pounds. Choice A (3,000 pounds) is too low as it underestimates the total weight. Choice C (4,100 pounds) and Choice D (5,000 pounds) are too high as they overestimate the total weight.
The table below shows the number of books checked out from a library over the course of 4 weeks. Which equation describes the relationship between the number of books (b) and weeks (w)?
- A. b = 10w + 2
- B. b = 5w + 10
- C. b = 8w + 12
- D. b = 4w + 20
Correct Answer: B
Rationale: The relationship between the number of books and weeks is best described by the equation b = 5w + 10. This is because the initial value of books checked out is 10, which indicates that even with 0 weeks, there are already 10 books checked out. The rate at which books are checked out per week is 5, as indicated by the coefficient of w. Therefore, the correct equation should be b = 5w + 10. Choices A, C, and D are incorrect because they do not represent the correct initial value or rate of increase for the given scenario.
Dr. Lee observed that 30% of all his patients developed an infection after taking a certain antibiotic. He further noticed that 5% of that 30% required hospitalization to recover from the infection. What percentage of Dr. Lee's patients were hospitalized after taking the antibiotic?
- A. 1.50%
- B. 5%
- C. 15%
- D. 30%
Correct Answer: A
Rationale: To find the percentage of Dr. Lee's patients hospitalized after taking the antibiotic, we need to calculate 30% of 5%. First, convert 30% and 5% to decimals: 30% = 0.30 and 5% = 0.05. Multiply 0.30 by 0.05 to get 0.015. To convert 0.015 to a percentage, multiply by 100, resulting in 1.5%. Therefore, only 1.50% of Dr. Lee's patients were hospitalized after taking the antibiotic. Choice A is correct. Choice B (5%) is incorrect as it represents the percentage of patients who developed an infection and not those hospitalized. Choices C (15%) and D (30%) are also incorrect percentages as they do not accurately reflect the proportion of hospitalized patients in this scenario.
University X requires some of its nursing students to take an exam before being admitted into the nursing program. In this year's class, half of the nursing students were required to take the exam, and three-fifths of those who took the exam passed. If this year's class has 200 students, how many students passed the exam?
- A. 120
- B. 100
- C. 60
- D. 50
Correct Answer: C
Rationale: If the incoming class has 200 students, then half of those students were required to take the exam. (200)(1/2) = 100. So 100 students took the exam, but only three-fifths of that 100 passed the exam. (100)(3/5) = 60. Therefore, 60 students passed the exam. The correct answer is 60. Choice A is incorrect as it miscalculates the number of students who passed the exam. Choice B is incorrect as it does not consider the passing rate of the exam. Choice D is incorrect as it is much lower than the correct answer.