Final answer:
To calculate the time to burn 1.5 gallons of gas, multiply the car's fuel efficiency by the volume of gas and then divide by the speed. The time taken is 0.84 hours or 50.4 minutes, which corresponds to answer choice (a) 50 minutes.
Step-by-step explanation:
The student asks about the time it will take to burn 1.5 gallons of gas in a car that has a fuel efficiency of 42 miles per gallon while driving at 75 miles per hour. To solve this, we need to calculate the distance that the car can travel on 1.5 gallons, which is 42 miles/gallon × 1.5 gallons = 63 miles. Since the student drives at 75 miles per hour, the time taken to travel 63 miles is 63 miles ÷ 75 miles/hour = 0.84 hours or 50.4 minutes. Hence, the correct answer is (a) 50 minutes.