which of the following is not a way to write 40 percent of n

ATI TEAS 7

TEAS Math Practice Test

1. Which of the following is NOT a way to write 40 percent of N?

A. 0.4N
B. N/40
C. 2/5 N
D. 40N/100

Correct answer: B

Rationale: The correct answer is B: N/40. To find 40% of N, you multiply N by 0.4, so 0.4N is the correct representation. Choice B, N/40, is incorrect because dividing N by 40 does not give you 40% of N. Choice C, 2/5 N, is equivalent to 40% of N since 2/5 is the same as 40% when simplified. Choice D, 40N/100, is also correct since 40% can be represented as 40/100, which simplifies to 0.4, making 40N/100 another valid way to write 40% of N.

2. In the problem 6 + 3 × 2, which operation should be completed first?

A. Multiplication
B. Addition
C. Division
D. Subtraction

Correct answer: A

Rationale: The correct answer is 'Multiplication.' According to the order of operations (PEMDAS), which stands for Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right), multiplication should be completed first. In the given expression, 3 × 2 should be solved before adding 6 to the result. This means that the multiplication operation should be prioritized over addition. Choices B, C, and D are incorrect because, in the order of operations, multiplication takes precedence over addition, division, and subtraction, respectively.

3. Which of the following lists is in order from least to greatest? 2−1 , −(4/3), (−1)3 , (2/5)

A. 2−1 , −(4/3), (−1)3 , (2/5)
B. −(4/3), (−1)3 , 2−1 , (2/5)
C. −(4/3), (2/5), 2−1 , (−1)3
D. −(4/3), (−1)3 , (2/5), 2−1

Correct answer: D

Rationale: To determine the correct order from least to greatest, start by simplifying the expressions. 2^(-1) = 1/2 and (-1)^3 = -1. Now, comparing the values, (-4/3) is the most negative, followed by -1, then (2/5), and finally 1/2. Therefore, the correct order is (-4/3), (-1)^3, (2/5), 2^(-1), making choice D the correct answer. Choices A, B, and C are incorrect because they do not follow the correct order from least to greatest as determined by comparing the values of the expressions after simplification.

4. In a research study, a researcher collects data on the number of hours spent studying and the grades students received. Which of the following is the dependent variable?

A. The number of hours spent studying
B. The grades students received
C. The subjects students studied
D. The number of students in the study

Correct answer: B

Rationale: The correct answer is B: 'The grades students received.' In this scenario, the grades students received are the dependent variable because they are influenced by the number of hours spent studying. The grades are the outcome that is being measured based on the manipulation or observation of the independent variable, which in this case is the number of hours spent studying. Choices A, C, and D are incorrect. The number of hours spent studying is the independent variable being manipulated or observed, the subjects students studied is not directly related to the dependent variable, and the number of students in the study is not the variable being measured or influenced by the independent variable.

5. A scientist is trying to determine how much poison will kill a rat the fastest. Which of the following statements is an example of an appropriate hypothesis?

A. Rats that are given lots of poison seem to die quickly.
B. Does the amount of poison affect how quickly the rat dies?
C. The more poison a rat is given, the quicker it will die.
D. Poison is fatal to rats.

Correct answer: C

Rationale: A valid hypothesis must be a testable statement that predicts a relationship between variables. Option C is the only statement that presents a clear cause-and-effect relationship between the amount of poison given and the time it takes for the rat to die. Option A is descriptive without predicting an outcome, option B is a question rather than a statement, and option D is a general fact about poison and rats, lacking a specific hypothesis for testing.