A boy walks to his school at a distance of 6 km with constant speed of 2.5 km/hr and walks both with a constant speed of 4 km/hr . His average speaks for the round trip is - Clay6.com, a Free resource for your JEE, AIPMT and Board Exam preparation

A boy walks to his school at a distance of 6 km with constant speed of 2.5 km/hr and walks both with a constant speed of 4 km/hr . His average speaks for the round trip is