which of the following describes a real world situation that could be modeled by

ATI TEAS 7

TEAS Test Practice Math

1. Which of the following describes a real-world situation that could be modeled by?

A. Courtney charges a $12 fee plus $2 per hour to babysit. Kendra charges a $10 fee plus $5 per hour. Write an equation to find the number of hours for which the two charges are equal.
B. Courtney charges a $2 fee plus $12 per hour to babysit. Kendra charges a $5 fee plus $10 per hour. Write an equation to find the number of hours for which the two charges are equal.
C. Courtney charges a $12 fee plus $2 to babysit. Kendra charges a $10 fee plus $5 to babysit. Write an equation to find the number of hours for which the two charges are equal.
D. Courtney charges $10 plus $2 per hour to babysit. Kendra charges $12 plus $5 per hour. Write an equation to find the number of hours for which the two charges are equal.

Correct answer: A

Rationale: In the given situation, Courtney charges a $12 fee plus $2 per hour to babysit, represented by the equation: 12 + 2h where h is the number of hours. Kendra charges a $10 fee plus $5 per hour, represented by the equation: 10 + 5h. To find the number of hours for which the two charges are equal, we set the two equations equal to each other: 12 + 2h = 10 + 5h. Solving for h gives h = 2. This means that the charges are equal after 2 hours of babysitting. Choice B is incorrect because the fee and hourly rates for Courtney and Kendra are reversed, leading to an incorrect equation. Choices C and D are incorrect as they do not accurately represent the given scenario of fees and hourly rates for babysitting by Courtney and Kendra.

2. A certain exam has 30 questions. A student gets 1 point for each question answered correctly and loses half a point for each question answered incorrectly; no points are gained or lost for questions left blank. If x represents the number of questions a student answers correctly and y represents the number of questions left blank, which of the following expressions represents the student's score on the exam?

A. x - y/2
B. x - y
C. 30 - (x + y)
D. 30 - x - y/2

Correct answer: A

Rationale: The student's score is calculated by adding the points earned for correct answers (x) and subtracting the points lost for incorrect answers (y/2). Therefore, the expression for the student's score on the exam is x - y/2. Option A is correct because it accurately represents this calculation. Option B (x - y) is incorrect as it does not account for the penalty of losing half a point for each incorrect answer. Option C (30 - (x + y)) is incorrect as it subtracts the total number of questions from the sum of correct and blank answers, which does not represent the scoring system. Option D (30 - x - y/2) is also incorrect as it incorrectly subtracts x from 30 and then deducts y divided by 2, which is not the correct scoring method for the exam.

3. As part of a study, a set of patients will be divided into three groups. 4/15 of the patients will be in Group Alpha, 2/5 in Group Beta, and 1/3 in Group Gamma. Order the groups from smallest to largest, according to the number of patients in each group.

A. Group Alpha, Group Beta, Group Gamma
B. Group Alpha, Group Gamma, Group Beta
C. Group Gamma, Group Alpha, Group Beta
D. Group Alpha, Group Beta, Group Gamma

Correct answer: B

Rationale: The correct order is Group Alpha, Group Gamma, Group Beta based on the common denominators of the fractions. To determine the order from smallest to largest, compare the fractions' numerators since the denominators are different. Group Alpha has 4/15 patients, Group Gamma has 1/3 patients, and Group Beta has 2/5 patients. Comparing the fractions' numerators, the order from smallest to largest is Group Alpha (4), Group Gamma (1), and Group Beta (2). Therefore, the correct order is Group Alpha, Group Gamma, Group Beta. Choice A is incorrect as it lists Group Beta before Group Gamma. Choice C is incorrect as it lists Group Gamma before Group Alpha. Choice D is incorrect as it lists Group Beta before Group Gamma, which is not in ascending order based on the number of patients.

4. Complete the following equation: 5 + 3 × 4 - 6 / 2 = ?

A. 5
B. 9
C. 11
D. 7

Correct answer: B

Rationale: To solve this equation, follow the order of operations (PEMDAS/BODMAS): First, perform multiplication and division from left to right. 3 × 4 equals 12, and 6 / 2 equals 3. Then, carry out addition and subtraction from left to right. 5 + 12 - 3 equals 14, not 9. Therefore, the correct answer is 14, making choice B the correct answer. Choices A, C, and D can be eliminated as they do not match the correct result obtained by following the order of operations.

5. What must you always use in all math?

A. PEMDAS
B. Variables
C. Conversion factors
D. Estimation

Correct answer: A

Rationale: The correct answer is A: PEMDAS. PEMDAS stands for the order of operations: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). It is a fundamental rule to follow in mathematics to ensure calculations are done correctly. Choices B, C, and D are incorrect as they do not encompass the essential rule that PEMDAS provides for solving mathematical expressions.