what is the probability of consecutively pulling two more orange blocks without replacement from a bag containing 3 orange blocks 5 green blocks and 4

ATI TEAS 7

Math Practice TEAS Test

1. What is the probability of consecutively pulling two more orange blocks, without replacement, from a bag containing 3 orange blocks, 5 green blocks, and 4 purple blocks?

A. 3/12
B. 3/55
C. 2/10
D. 1/3

Correct answer: B

Rationale: To calculate the probability of consecutively pulling two more orange blocks without replacement, we first determine the probability of pulling an orange block on the first draw, which is 3/12 (3 orange blocks out of 12 total blocks). After removing one orange block, there are only 11 blocks left, so the probability of pulling another orange block on the second draw is 2/11. To find the combined probability, we multiply the probabilities together: (3/12) * (2/11) = 6/132 = 3/55. Therefore, the correct answer is B. Choice A (3/12) incorrectly simplifies the probability before calculating the second draw. Choice C (2/10) does not consider the specific number of orange blocks in the bag. Choice D (1/3) does not account for the reduced number of blocks after the first draw.

2. Prizes are to be awarded to the best pupils in each class of an elementary school. The number of students in each grade is shown in the table, and the school principal wants the number of prizes awarded in each grade to be proportional to the number of students. If there are twenty prizes, how many should go to fifth-grade students? Grade 1 2 3 4 5 Students 35 38 38 33 36

A. 5
B. 4
C. 7
D. 3

Correct answer: C

Rationale: To determine how many prizes should be awarded to 5th-grade students, we need to set up the proportion of the number of 5th-grade students to the total number of students in the school. The total number of students is 35 + 38 + 38 + 33 + 36 = 180 students. To find the proportion of 5th-grade students, it would be 36/180 = 0.2. Since there are 20 prizes to be awarded, multiplying 0.2 by 20 gives us 4, which means 4 prizes should go to the 5th-grade students. Therefore, the correct answer is 4. Choice A (5) is incorrect as it does not align with the proportional distribution. Choice B (4) is the correct answer, as calculated. Choice C (7) is incorrect as it exceeds the total number of prizes available. Choice D (3) is incorrect as it does not match the proportional distribution based on the number of students.

3. Which of the following statements is true?

A. The mean is less than the median
B. The mode is greater than the median
C. The mode is less than the mean, median, and range
D. The mode is equal to the range

Correct answer: A

Rationale: The mean is the average of a set of numbers, while the median is the middle value when the numbers are arranged in order. If a set of numbers is skewed to one side with some outliers, the mean can be influenced by these extreme values, causing it to be greater or less than the median. In cases of skewed distribution, the mean typically shifts towards the direction of the outliers, making it less than the median. Choice B is incorrect because the mode, which is the most frequent number in a dataset, may or may not be greater than the median. Choice C is incorrect because the mode can be greater than the mean or median, depending on the data. Choice D is incorrect because the mode, representing the most frequent value, has no direct relationship with the range, which is the difference between the highest and lowest values in a dataset.

4. What defines a composite number?

A. A number with only two factors
B. A number that is a fraction
C. A number with more than 2 factors
D. A number with exactly two factors

Correct answer: C

Rationale: A composite number is a positive integer greater than one that has more than two factors. Choice A is incorrect because a number with only two factors is a prime number. Choice B is incorrect as being a fraction does not define a composite number. Choice D is incorrect because a number with exactly two factors is a prime number, not a composite number.

5. You measure the width of your door to be 36 inches. The true width of the door is 75 inches. What is the relative error in your measurement?

A. 0.52%
B. 0.01%
C. 0.99%
D. 0.10%

Correct answer: A

Rationale: The relative error is calculated using the formula: (|Measured Value - True Value| / True Value) * 100%. Substituting the values given, we have (|36 - 75| / 75) * 100% = (39 / 75) * 100% ≈ 0.52 * 100% = 0.52%. Therefore, the relative error in measurement is approximately 0.52%. Choice A is correct because it reflects this calculation. Choice B is incorrect as it represents a lower relative error than the actual value obtained. Choice C is incorrect as it overestimates the relative error. Choice D is incorrect as it underestimates the relative error.