Ashneer completes a journey in 16 hours . He travels the first half of the journey at the speed of 35 km/h and the second half of it at the speed of 45 km/h.  The total distance of the journey is:

630 kms

                            ( 1st half )     :   ( 2nd half )   

ratio of Speed    =    35 km/h   :     45 km/h 

                                         7      :     9

as , Distance = Speed × Time  

That means ratio of speed and distance is same ratio of speed and time are reverse to each other . 

                                 ( 1st half )     :    ( 2nd half )   

 ratio of  Distance   =              7      :        9

 ratio of Time         =               9     :       7 

⇒ ( 9 + 7 ) R = 16 hours  ( according to question )

⇒ 16R = 16 hours 

⇒ 1R = 1 hour

Now, Total Distance = Speed × Time

                             = (35 km/h × 9) + (45 km/h × 7)

                             = 315 + 315 = 630 km