A person walks along a straight road from his house to a marked 2.5kms away with a speed of 5 km/hr and instantly turns back and reaches his house with a speed of 7.5 kms/hr. The average speed of the person during the time interval 0 to 50 minutes is (in m/sec)

A person walks along a straight road from his house to a marked 2.5kms

1.	A person walks along a straight road from his house to a marked 2.5kms away with a speed of 5 km/hr and instantly turns back and reaches his house with a speed of 7.5 kms/hr. The average speed of the person during the time interval 0 to 50 minutes is (in m/sec)
Answer» `4(2)/(3)` `(5)/(3)` `(5)/(6)` `(1)/(3)` Answer :B