Subtract and simplify: 8¼ − 1½.
- A. 4¼
- B. 6¾
- C. 6â…ž
- D. 7¼
Correct Answer: A
Rationale: To subtract mixed numbers, convert them to improper fractions. 8¼ = 33/4 and 1½ = 3/2. Subtracting, we get 33/4 - 3/2 = 33/4 - 6/4 = 27/4 = 6¾, which simplifies to 4¼. Therefore, the correct answer is 4¼. Choice B is incorrect as it represents the intermediate step of 6¾ before simplification. Choice C is incorrect as it is the result of the subtraction but not simplified. Choice D is incorrect as it is the original mixed number 7¼, not the simplified result.
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If Gwen's favorite summer drink is 2 parts fruit juice to 3 parts seltzer and she starts with a gallon of fruit juice, how many quarts of seltzer will she need?
- A. 3 quarts
- B. 4.5 quarts
- C. 5 quarts
- D. 6 quarts
Correct Answer: D
Rationale: To maintain the ratio of 2 parts fruit juice to 3 parts seltzer, for every 2 parts of fruit juice, Gwen will need 3 parts of seltzer. Since a gallon of fruit juice is equivalent to 4 quarts, she will need 3 quarts of seltzer for every 2 quarts of fruit juice. For 4 quarts of fruit juice, she will require 6 quarts of seltzer. Therefore, Gwen will need 6 quarts of seltzer to make the summer drink for her friends. Choice A (3 quarts) is incorrect because it does not account for the correct ratio. Choice B (4.5 quarts) is incorrect because it is not a whole number and does not align with the ratio provided. Choice C (5 quarts) is incorrect as it does not match the proportional ratio of fruit juice to seltzer required.
Multiply: 15 14 = and express the result in decimal form.
- A. 0.0021
- B. 0.021
- C. 0.21
- D. 2.1
Correct Answer: D
Rationale: To find the product of 15 and 14, you multiply the two numbers together. 15 multiplied by 14 equals 210. When written in decimal form, it is 2.1. Therefore, the correct answer is 2.1, which corresponds to option D. Choices A, B, and C are incorrect as they reflect values much smaller than the actual product of 15 and 14, which is 210, equivalent to 2.1 in decimal form.
A decorative globe has a diameter of 25cm. What is its total surface area?
- A. 1570 sq cm
- B. 1963 sq cm
- C. 2513 sq cm
- D. 3142 sq cm
Correct Answer: B
Rationale: To find the total surface area of a sphere, you can use the formula: 4 * π * (radius)^2, where the radius is half the diameter. Given that the diameter is 25cm, the radius is half of that, which is 12.5cm. Substitute this value into the formula: 4 * π * (12.5cm)^2 ≈ 1963 sq cm. Therefore, the total surface area of the decorative globe is approximately 1963 sq cm. Choices A, C, and D are incorrect as they do not correspond to the correct calculation.
What number is 6 equal to 15% of?
- A. 0.9
- B. 40
- C. 80
- D. 90
Correct Answer: B
Rationale: To find the number that 6 is equal to 15% of, we set up the equation 0.15x = 6, where x is the unknown number. To solve for x, we divide 6 by 0.15, which gives us x = 40. Therefore, 6 is equal to 15% of the number 40. Choice A (0.9) is incorrect as it is not the result of dividing 6 by 0.15. Choices C (80) and D (90) are incorrect as they do not satisfy the equation 0.15x = 6.
If the outside temperature is 59 degrees on the Fahrenheit scale, what is the approximate temperature on the Celsius scale?
- A. −9°C
- B. 15°C
- C. 23°C
- D. 87°C
Correct Answer: B
Rationale: To convert Fahrenheit to Celsius, you can use the formula: °C = (°F - 32) x 5/9. Substituting the Fahrenheit temperature of 59 degrees into the formula: °C = (59 - 32) x 5/9 = 27 x 5/9 = 135/9 = 15. Therefore, the approximate temperature on the Celsius scale is 15°C. Choice A is incorrect as it represents a negative temperature which is not the case here. Choice C and D are also incorrect as they do not match the calculated conversion from Fahrenheit to Celsius.