Tell the average speed of the person during whole journey :
Answer: (1) 37.5 km/hr
Solution:- Let the total distance from point P to Q = X Km.
Then time taken from point P to Q =X/50 hrs
and time taken from point Q to P =X/30 hrs
Then, Average speed = Total covered distance/ Total taken time
=2 X x 150/8 X
Then, average speed of a person is 37.5 km/hr
So, correct answer is option (1) 37.5 km/hr.