Answer:
20 km.
Explanation:
First, divide 15 by 3 to find out how many kilometers Arun can walk in a single hour.
15/3=5
To find out how far he can walk in 4 hours, multiply 4 by the number of kilometers he can walk in an hour, which is 5.
4x5=20
Therefore, Arun can walk 20 km in 4 hours.
Hope this helps you out and have a great day (^人^)