It is urgent to solve this problem with inequality Xiaohua left home at 10:10 to catch the 11:00 train. It is known that his home is 10 kilometers away from the station. After he left home, he walked at a speed of 3 kilometers per hour for 5 minutes. Then he called the bus to the station and asked how many kilometers the bus should walk at least per hour so as not to miss the train?

It is urgent to solve this problem with inequality Xiaohua left home at 10:10 to catch the 11:00 train. It is known that his home is 10 kilometers away from the station. After he left home, he walked at a speed of 3 kilometers per hour for 5 minutes. Then he called the bus to the station and asked how many kilometers the bus should walk at least per hour so as not to miss the train?

Let the velocity be X
5 minutes = 5 / 60 = 1 / 12 hours
So 3 × 1 / 12 = 1 / 4 km
Total time = 50 minutes = 5 / 6 hours
So the car distance is 10-1 / 4 = 39 / 4 km
Time 5 / 6-1 / 12 = 3 / 4 hours
So (3 / 4) x ≥ 39 / 4
x≥13
A: the car travels at least 13 kilometers per hour