A train travels at 70 mph for 6 hours. How far did it travel?

Correct Answer: D

Rationale: In this scenario, the correct answer is D) 420 miles. To calculate the distance traveled by the train, we use the formula distance = speed x time. The train travels at 70 mph for 6 hours, so the distance is 70 x 6 = 420 miles. Option A (490 miles) and Option B (490 miles) are incorrect as they are the same and do not match the correct calculation. Option C (540 miles) is incorrect because it is not the result of multiplying the speed and time given in the question. Educationally, this question assesses the student's ability to apply the basic formula for distance, speed, and time. It also tests their understanding of units (mph for speed and hours for time) and how to correctly apply them in a real-world context. Understanding this concept is crucial for solving various problems involving distance, time, and speed in mathematics and in real-life situations such as physics and engineering.

Correct Answer: A

Rationale: To find the average speed, first, convert 45 minutes to hours (45/60 = 0.75 hours). Then, divide the distance by the time: 5 miles · 0.75 hours = 6.67 mph. Choice A is correct because it accurately calculates the average speed based on the distance covered and time taken. Choice B is incorrect as it does not consider the time taken to cover the distance. Choice C is incorrect as it is higher than the calculated speed. Choice D is incorrect as it is higher and does not match the calculated average speed.

Correct Answer: B

Rationale: Since each syringe holds 3ml of liquid, to measure 15ml of liquid, you would need to divide 15ml by 3ml/syringe. This calculation gives you 5 syringes needed to measure 15ml of liquid. Choice A (3 syringes) is incorrect because 3 syringes would only hold 9ml of liquid, not 15ml. Choice C (7 syringes) and Choice D (9 syringes) are incorrect as they would result in an excess amount of liquid, which is not needed.

Correct Answer: C

Rationale: In this scenario, to find the total amount of medication administered in 3 hours, we first calculate the total drops administered by multiplying the drops per minute by the total minutes. This gives us 40 drops/minute * 180 minutes = 7200 drops. Then, we convert the drops to milligrams by multiplying the total drops by the amount of medication in each drop, which is 1mg. Therefore, 7200 drops * 1mg/drop = 7200mg. The correct answer is 7,200mg. Choice A is incorrect as it miscalculates the total amount. Choice B is incorrect as it doubles the correct answer. Choice D is incorrect as it quadruples the correct answer.

Correct Answer: C

Rationale: Rationale: The correct answer is obtained by applying the formula for the circumference of a circle, which is \(C = \pi \times d\), where \(d\) is the diameter of the circle. By substituting the given diameter of 40cm into the formula and performing the calculation, we find that the circumference of the pizza is 125.6cm.