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A bottle of hand sanitizer contains 70% alcohol. If 5ml of sanitizer are used, how much pure alcohol is present?
- A. 1.4ml
- B. 2.1ml
- C. 2.8ml
- D. 3.5ml
Correct Answer: B
Rationale: Rationale:
- If the hand sanitizer contains 70% alcohol, it means that 70% of the 5ml used is pure alcohol.
- To find the amount of pure alcohol present, we calculate 70% of 5ml: 0.7 * 5ml = 3.5ml.
- Therefore, when 5ml of sanitizer are used, there are 3.5ml of pure alcohol present.
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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.
At the fair, Serena sold 6 fewer balloons than Tommy, who sold 2 more balloons than Uri. If Uri sold 28 balloons, how many did Serena sell?
- A. 20
- B. 22
- C. 24
- D. 32
Correct Answer: C
Rationale: If Uri sold 28 balloons, Tommy sold 28 + 2 = 30 balloons. Since Serena sold 6 fewer balloons than Tommy, she sold 30 - 6 = 24 balloons. Therefore, Serena sold 24 balloons. Choice A, 20 balloons, is incorrect because it doesn't consider the difference in sales between Serena and Tommy. Choice B, 22 balloons, is incorrect as it doesn't account for the correct relation between Tommy and Serena's sales. Choice D, 32 balloons, is incorrect as it doesn't align with the given information about the sales differences.
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.
Solve for x: 2 : 5 :: 64 : x
- A. 32
- B. 70
- C. 128
- D. 160
Correct Answer: C
Rationale: The symbol '::' represents a proportion in which the first pair of numbers is related to the second pair of numbers. To solve for x in the proportion 2 : 5 :: 64 : x, you can set up a proportion equation: 2/5 = 64/x. Cross-multiplying gives you 2x = 5 * 64, which simplifies to 2x = 320. Dividing both sides by 2, you get x = 160. Therefore, x = 128 is the correct answer. Choice A (32) is incorrect as it is not the result of solving the proportion equation. Choice B (70) is incorrect as it is not related to the given proportion. Choice D (160) is a common mistake made by wrongly interpreting the equation; the correct value of x is 128.
How many kilograms are equivalent to 20 pounds?
- A. 9 kilograms
- B. 16 kilograms
- C. 44 kilograms
- D. 3 kilograms
Correct Answer: A
Rationale: To convert pounds to kilograms, you need to multiply the number of pounds by 0.4536. Therefore, to find out how many kilograms are in 20 pounds, you would calculate 20 x 0.4536 = 9.072 kilograms, which is approximately 9 kilograms. Choice A is correct. Choice B (16 kilograms), Choice C (44 kilograms), and Choice D (3 kilograms) are all incorrect conversions of pounds to kilograms.