Last night at the hospital, 76 babies were born. Of the births, 45% were girls. How many boys were born last night? (Round your numbers to the nearest whole number).

Correct Answer: A

Rationale: When 45% of the babies were girls, it means the remaining 55% were boys. To determine the number of boys, calculate 55% of 76, which equals approximately 41.8, rounding up to 42. Therefore, 42 boys were born last night at the hospital. Choice B, C, and D are incorrect as they do not reflect the accurate calculation of the number of boys born.

Correct Answer: B

Rationale: To earn the same amount that Tim makes in 4 hours, Tim earns $30 per hour, totaling $120 in 4 hours. Joe earns $20 per hour, so to match Tim's earnings in 4 hours, Joe must work 2 hours more than Tim. Therefore, Joe needs to work 2 hours more than Tim to earn the same amount that Tim makes in 4 hours. Choices A, C, and D are incorrect as they do not accurately reflect the additional hours Joe needs to work compared to Tim to earn the same amount in 4 hours.

Correct Answer: C

Rationale: Reducing the rat's speed by 50% means it will take twice as long to finish the maze. Since the original time is 3 minutes, doubling that gives 6 minutes. Therefore, the total time will be 6 minutes, making the correct answer C. Choice A (3 minutes) is the original time it takes the rat to finish the maze, not the time with the backpack. Choice B (4 minutes) is not correct as reducing the speed by 50% would double the original time. Choice D (1.5 minutes) is incorrect as halving the time is not the effect of reducing the speed by 50%.

Correct Answer: B

Rationale: In the metric system, there are 1000 grams in 1 kilogram. To convert kilograms to grams, you multiply the number of kilograms by 1000. Therefore, 4 kilograms would equal 4000 grams. Choice A (400 grams) is incorrect because it is the result of multiplying by 100, not 1000. Choice C (40 grams) is incorrect as it is the result of dividing by 1000 instead of multiplying. Choice D (100 grams) is incorrect as it is a random figure and not the correct conversion from kilograms to grams.

Correct Answer: A

Rationale: To find the cost of 1 book, divide the total cost by the number of books: $4 / 3 = $1.33 per book. To determine the cost of 6 books, multiply the cost per book by 6: $1.33 * 6 = $8. Therefore, purchasing 6 books will cost $8. Choice B, $12, is incorrect as it incorrectly doubles the cost of 3 books. Choice C, $6, is incorrect as it is half the cost of 3 books. Choice D, $10, is incorrect as it does not accurately calculate the cost of 6 books based on the given information.

Correct Answer: B

Rationale: The correct answer is B: 128 oz. There are 128 ounces in a gallon. This is a standard conversion factor in the US customary system. Choices A, C, and D are incorrect because they do not reflect the accurate conversion of ounces in a gallon.

Correct Answer: D

Rationale: When a die is rolled, there are 3 odd numbers (1, 3, 5) out of a total of 6 possible outcomes. The probability of rolling an odd number is calculated by dividing the number of favorable outcomes (3) by the total number of outcomes (6), resulting in a probability of 3/6 or 50%. Therefore, the correct answer is D. Choices A, B, and C are incorrect because they do not reflect the correct probability calculation for rolling an odd number on a standard six-sided die.

Correct Answer: C

Rationale: To convert quarts to gallons, remember that 1 gallon equals 4 quarts. Therefore, 16 quarts · 4 quarts/gallon = 4 gallons. The correct answer is 4 gallons because each gallon contains 4 quarts. Choice A (1 gallon) is incorrect because 1 gallon is equal to 4 quarts, not 16 quarts. Choice B (8 gallons) is incorrect as it miscalculates the conversion. Choice D (4.5 gallons) is incorrect because it doesn't align with the conversion rate of 4 quarts per gallon.

Correct Answer: C

Rationale: Since 1 gram (g) equals 1000 milligrams (mg) and 1 g = 1 teaspoon (tsp), the prescribed 1000 mg is equal to 1 tsp. Therefore, you will give 1 teaspoon of the Benadryl liquid. Choices A, B, and D are incorrect because they do not correspond to the correct conversion of 1 g to 1 tsp, which is essential in solving this dosage calculation.