Question

Roselyn is driving to visit her family, who live 150 kilometers away. Her average speed is 60 kilometers per hour. The car's tank has 20 liters of fuel at the beginning of the drive, and its fuel efficiency is 6 kilometers per liter. Fuel costs 0.60 dollars per liter. How long can Roselyn drive before she runs out of fuel?

a) 4 hours
b) 2 hours
c) 5 hours
d) 3 hours

Answer 1

Roselyn can drive for 2 hours before she runs out of fuel, calculated by dividing the total distance she can travel on a full tank (120 km) by her average speed (60 km/h).

Step-by-step explanation:

To calculate the time Roselyn can drive before she runs out of fuel, we need to use the car's fuel efficiency. The car consumes 1 liter of fuel for every 6 kilometers. With a 20-liter fuel tank, we can determine the total distance Roselyn can travel on a full tank:

Total distance = Fuel efficiency × Fuel volume
= 6 km/liter × 20 liters
= 120 km

Now, we can calculate the time it will take for Roselyn to run out of fuel by dividing the total distance she can travel on a full tank by her average speed:

Time = Total distance / Average speed
= 120 km / 60 km/h
= 2 hours

Therefore, option b) 2 hours is the correct answer.