প্রশ্ন সংশোধন করুন
প্রশ্ন:
A man travels a certain distance at a rate of 20 miles an hour and returns at the rate of 30 miles an hour . What is his average speed ?
A man travels a certain distance at a rate of 20 miles an hour and returns at the rate of 30 miles an hour . What is his average speed ?