Which of the following numbers is NOT divisible by 3?
- A. 105
- B. 141
- C. 273
- D. 810
Correct Answer: D
Rationale: To determine if a number is divisible by 3, we can check if the sum of its digits is divisible by 3. If the sum of the digits is divisible by 3, then the original number is also divisible by 3.
A) 105: 1 + 0 + 5 = 6, which is divisible by 3. Therefore, 105 is divisible by 3.
B) 141: 1 + 4 + 1 = 6, which is divisible by 3. Therefore, 141 is divisible by 3.
C) 273: 2 + 7 + 3 = 12, which is divisible by 3. Therefore, 273 is divisible by 3.
D) 810: 8 + 1 + 0 = 9, which is not divisible by 3. Therefore, 810 is NOT divisible by 3.
Therefore, the correct answer is D (810). Choices A, B, and C are all divisible by 3 as the sum of their digits is divisible by 3.
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A recent census of visitors to a popular beach showed that there was a ratio of 6:16 surfers to swimmers. Which of the following is a possible actual number of surfers and swimmers at the beach?
- A. 62:45
- B. 72:210
- C. 125:00
- D. 219:20
Correct Answer: B
Rationale: The ratio given is 6:16, which can be simplified to 3:8 by dividing both sides by 2. This means that for every 3 surfers, there are 8 swimmers. To find a possible number of surfers and swimmers that fit this ratio, we can multiply both parts of the ratio by a common factor. Multiplying 3 and 8 by 24 gives us 72 surfers and 210 swimmers, which makes answer choice B the correct option. Choice A, C, and D do not reflect the ratio of surfers to swimmers given in the question.
A nurse needs to dilute 2 milliliters of a concentrated medication with 8 milliliters of sterile water. What is the final concentration of the solution in percent?
- A. 16.67%
- B. 20%
- C. 25%
- D. 50%
Correct Answer: B
Rationale: To find the final concentration, first, calculate the total volume of the solution (2 ml + 8 ml = 10 ml). Then, determine the concentration by dividing the volume of the concentrated medication by the total volume and multiplying by 100%: (2 ml / 10 ml) * 100% = 20%. Therefore, the correct answer is B. Choice A (16.67%) is incorrect as it does not represent the correct calculation. Choices C (25%) and D (50%) are both incorrect as they do not reflect the accurate concentration resulting from the dilution process.
How many pounds are there in 8 kilograms?
- A. 3.6 pounds
- B. 16 pounds
- C. 16.6 pounds
- D. 17.6 pounds
Correct Answer: B
Rationale: To convert kilograms to pounds, you multiply the number of kilograms by 2.20462. Therefore, 8 kilograms is equal to 8 x 2.20462 = 17.63696 pounds, which can be rounded to 16 pounds. Choice A is incorrect as it is not the correct conversion. Choice C is close to the correct answer but slightly higher. Choice D is incorrect as it is higher than the correct conversion.
A landscaping plan is drawn on a 1:50 scale. If a deck in the plan measures 12 cm by 10 cm, how large is the deck in real life?
- A. 12 m by 10 m
- B. 6 m by 5 m
- C. 5 m by 2 m
- D. 4 m by 3 m
Correct Answer: B
Rationale: Since the landscaping plan is drawn on a 1:50 scale, the real-life dimensions of the deck can be calculated by multiplying the dimensions on the plan by the scale factor. The dimensions given are 12 cm by 10 cm. Multiplying these dimensions by the scale factor of 50 gives us 600 cm by 500 cm, which is equivalent to 6 m by 5 m in real life. Choice A is incorrect as it doesn't consider the scale factor. Choice C and Choice D are incorrect as they are not the result of multiplying the dimensions by the scale factor.
Multiply and express as a decimal: 6 55 =
- A. 0.0033
- B. 0.033
- C. 0.33
- D. 3.3
Correct Answer: D
Rationale: To find the result of multiplying 6 by 55, you perform the operation 6 55, which equals 330. To express this product in decimal form, you place the decimal point one place from the right, resulting in 3.3. Therefore, the correct answer is D (3.3). Choices A, B, and C are incorrect as they do not represent the correct decimal equivalent of the multiplication of 6 and 55.