A task about a dog: there is point A and point B, 30 km apart. A person from A walks at 4 km/h, from B at 6 km/h towards each other. A dog runs between them at 20 km/h. How many kilometers will the dog run before the people meet?

To find out how many kilometers a dog will run, first determine the time it takes for two people to meet.

The total distance between them is 30 km. The closing speed is the sum of their speeds: 4 km/h + 6 km/h = 10 km/h.

Time until they meet: 30 km / 10 km/h = 3 hours.

The dog runs at a speed of 20 km/h during this time, so it will run:

20 km/h × 3 hours = 60 km.