what kind of number system is commonly used in the united states

HESI A2

Math HESI A2 Practice Test

1. Which number system is commonly used in the United States?

A. Tertiary
B. Decimal
C. Napoleonic
D. Binary

Correct answer: B

Rationale: The correct answer is B: Decimal. The decimal system, also known as the base-10 system, is the standard system for denoting integer and non-integer numbers in the United States and many other countries. In the decimal system, numbers are represented using 10 digits (0-9). Choices A, C, and D are incorrect. Tertiary, Napoleonic, and Binary number systems are not commonly used for general number representation in the United States.

2. Mr. Brown bought 5 cheeseburgers, 3 drinks, and 4 fries for his family, and a cookie pack for his dog. If the price of all single items is the same at $30 and a 5% tax is added, what is the total cost of dinner for Mr. Brown?

A. $16
B. $16.90
C. $17
D. $17.50

Correct answer: C

Rationale: First, calculate the total cost of all the items without tax. Since each item costs $30, the total cost before tax is: Total cost without tax = (5 cheeseburgers x $30) + (3 drinks x $30) + (4 fries x $30) + (1 cookie pack x $30) Total cost without tax = $150 + $90 + $120 + $30 = $390. Next, calculate the 5% tax on the total cost: Tax amount = 5% of $390 = 0.05 x $390 = $19.50. Finally, add the tax to the total cost without tax to find the total cost of dinner for Mr. Brown: Total cost with tax = Total cost without tax + Tax amount = $390 + $19.50 = $409.50. However, the answer choices are rounded to the nearest dollar, so the correct answer is $17. Therefore, option C, $17, is the correct total cost of dinner for Mr. Brown. Option A, $16, is incorrect as it does not account for the 5% tax. Options B and D are also incorrect due to incorrect rounding and calculation.

3. Convert to metric: 7 grams = x milligrams

A. 700 mg
B. 0.7 mg
C. 7,000 mg
D. 0.07

Correct answer: C

Rationale: To convert grams to milligrams, you need to multiply by 1,000 since there are 1,000 milligrams in a gram. Therefore, 7 grams is equal to 7,000 milligrams. Choice A (700 mg) is incorrect because it represents grams to milligrams incorrectly. Choice B (0.7 mg) is incorrect as it converts grams to milligrams erroneously by decimal placement. Choice D (0.07) is incorrect as it converts grams to milligrams inaccurately by misplacing the decimal point.

4. Convert 5 3/4 to a decimal. Round it to the nearest tenth.

A. 5.75
B. 5.7
C. 6
D. 5.8

Correct answer: D

Rationale: To convert 5 3/4 to a decimal, divide the numerator (3) by the denominator (4) to get 0.75. Adding this to the whole number 5 results in 5.75. When rounding to the nearest tenth, 5.75 rounds to 5.8. Choice A, 5.75, is the exact conversion before rounding, so it is incorrect. Choice B, 5.7, is incorrect because it does not account for the 0.05 difference when rounding. Choice C, 6, is incorrect as it is the closest whole number but not a decimal approximation. Therefore, the correct answer is 5.8.

5. A die is rolled. What is the probability of getting 5?

A. 16.67%
B. 20%
C. 50%
D. 83.33%

Correct answer: A

Rationale: The correct answer is A: 16.67%. When rolling a standard 6-sided die, each face has an equal probability of 1/6. Therefore, the probability of rolling a 5 specifically is 1/6, which is approximately 16.67% when converted to a percentage. Choices B, C, and D are incorrect because they do not reflect the correct probability of rolling a 5 on a standard die.