How to Calculate Winning Time in a Race?

Question:

If Sally can pedal her bicycle 20 km in 2 h, while Antonio can pedal his bicycle 18 km in an hour and a half, and both enter a 24 km race pedaling at the same rates, which one will win the race and by how much time?

1) Sally and Antonio will tie.

2) Sally will win by 0.4 h.

3) Antonio will win by 0.4 h.

4) Antonio will win by 0.5 h.

Answer:

Antonio will win the race by 0.4 hours.

Explanation:

To determine the winner of the race and the winning time difference, we need to calculate the time each cyclist takes to complete the 24 km race at their respective speeds.

Sally's speed is 20 km / 2 h = 10 km/h. Therefore, it will take Sally 24 km / 10 km/h = 2.4 hours to finish the race.

Antonio's speed is 18 km / 1.5 h = 12 km/h. It will take Antonio 24 km / 12 km/h = 2 hours to complete the race.

Since Antonio finishes the race in 2 hours, while Sally takes 2.4 hours, Antonio will win the race by 0.4 hours (24 minutes).