Nokea
Find the value of x if x:15=120:225.
- A. x=8
- B. x=10
- C. x=6
- D. x=12
Correct Answer: A
Rationale: To solve x:15=120:225, set it up as a proportion: x/15 = 120/225. Simplify the right-hand side: 120/225 = 8/15. Now, solve for x by cross-multiplying: x = 8. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not align with the correct calculations.
You may also like to solve these questions
5\7 + 3\14 = ?
- A. 13\14
- B. 10/14
- C. 11/14
- D. 12/14
Correct Answer: A
Rationale: To add fractions with different denominators, first find a common denominator. The least common denominator between 7 and 14 is 14. Convert 5/7 to 10/14:
5
/
7
=
10
/
14
5/7=10/14
Now add the two fractions:
10
/
14
+
3
/
14
=
13
/
14
10/14+3/14=13/14
A researcher is collecting data on patient satisfaction. Out of 150 patients surveyed, 120 reported being satisfied with their care. What percentage of the patients were satisfied?
- A. 80%
- B. 75%
- C. 85%
- D. 90%
Correct Answer: A
Rationale: To find the percentage of satisfied patients, divide the number of satisfied patients by the total number of patients surveyed and multiply by 100. In this case, 120 (satisfied patients) · 150 (total patients surveyed) x 100 = 80%. Therefore, 80% of the patients were satisfied. Choice B (75%), C (85%), and D (90%) are incorrect percentages as the actual percentage of satisfied patients is 80%.
A lampshade is shaped like a frustum of a cone, with base diameters of 20cm and 10cm and a height of 15cm. What is its volume?
- A. 625 cu cm
- B. 1250 cu cm
- C. 1875 cu cm
- D. 2500 cu cm
Correct Answer: C
Rationale: To find the volume of the frustum of a cone, divide it into two cones and calculate their volumes separately. The formula for the volume of a cone frustum involves the radii of both bases and the height. The volume of the frustum cone can be calculated as V = 1/3 * π * h * (R^2 + r^2 + R * r), where R is the larger radius, r is the smaller radius, and h is the height. Substituting the values, V = 1/3 * π * 15 * (10^2 + 20*10 + 20^2) = 1875 cu cm. Therefore, the correct answer is 1875 cu cm. Choice A, B, and D are incorrect as they do not correspond to the correct calculation of the frustum's volume.
Scientific notation is a way to represent very large or small numbers in a compact form. If a number is written as 4.82 x 10^3, what is the value of the number in standard form?
- A. 0.004 82
- B. 0.482
- C. 4820
- D. 4820000
Correct Answer: C
Rationale: Rationale:
When a number is written in scientific notation as \(a \times 10^n\), the value of the number in standard form is obtained by multiplying \(a\) by \(10^n\). In this case, the number is \(4.82 \times 10^3\). To convert this to standard form, we multiply 4.82 by \(10^3\), which means moving the decimal point 3 places to the right.
\(4.82 \times 10^3 = 4820\)
Therefore, the value of the number in standard form is 4820, which corresponds to option C.
A set of temperature readings has a range of 5 degrees Celsius. What does this tell you about the data?
- A. The average temperature is 5 degrees Celsius.
- B. All temperatures are within 5 degrees of each other.
- C. The difference between the highest and lowest temperatures is 5 degrees.
- D. There are exactly 5 temperatures in the set.
Correct Answer: C
Rationale: Option A is incorrect because the range of 5 degrees does not necessarily mean that the average temperature is 5 degrees Celsius. The average temperature could be any value within the range. Option B is incorrect because the range of 5 degrees does not mean that all temperatures are within 5 degrees of each other. It only indicates the difference between the highest and lowest temperatures. Option C is correct because the range of 5 degrees specifically refers to the difference between the highest and lowest temperatures in the set. This is a common definition of range in statistics. Option D is incorrect because the range of 5 degrees does not determine the number of temperatures in the set. The set could have more or fewer than 5 temperatures.