Correct Answer: A

Rationale: The correct answer is A: 16. When you multiply 8 by 2, the result is 16. Choice B (22), Choice C (24), and Choice D (32) are incorrect as they do not represent the correct multiplication of 8 by 2.

Correct Answer: D

Rationale: To multiply 54 by 45, you should multiply the two numbers together: 54 x 45 = 2430. The decimal point is placed after counting the total decimal places in the numbers being multiplied. As there are no decimal places in the numbers 54 and 45, the result is 2430, which is correctly expressed as 24.3 when considering the decimal point placement. Choice A (0.0243) and Choice B (0.243) are incorrect as they represent fractions of 2430. Choice C (2.43) is incorrect as it incorrectly places the decimal point one place before the actual result.

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.

Correct Answer: C

Rationale: To express the ratio 12:15 as a percentage, you need to find the total parts in the ratio (12 + 15 = 27), then divide one part by the total (12 · 27 = 0.4444). Finally, convert the decimal to a percentage by multiplying by 100 (0.4444 x 100 = 44.44%). Therefore, the ratio 12:15 is equivalent to 44.44% when rounded to two decimal places, which is closest to 75.25% among the answer choices. Choices A, B, and D are incorrect as they do not represent the correct percentage equivalent of the ratio 12:15.

Correct Answer: B

Rationale: To determine how much you save per bar when buying a value pack of 8 bars for $20, calculate the individual price per bar by dividing the total price by the number of bars: $20 · 8 = $2.50 per bar. When the pack price is lower than the individual price, you save money. The saving per bar is found by subtracting the pack price from the individual price: $2.50 (individual price) - $2.50 (pack price) = $0.40. Therefore, you save 40 cents per bar by purchasing the value pack. Choice A, 15¢, is incorrect because the actual saving is $0.40. Choice C, 75¢, is incorrect as it doesn't match the calculated saving. Choice D, $1.20, is incorrect as it is not the actual amount saved per bar.