A person covers a certain distance with certain speed if he increases his speed by 05km/hr then he reach 5 min early . Find the time taken by man with his initial speed ,  if his initial speed is 25 km/hr .

30 min

Initial speed = 25 km/hr 

And speed increases by 5 km/hr ,

Increased speed = ( 25 + 5 ) km/hr= 30 km/hr

Ratio             initial speed     :      increased speed

                         25              :           30 

speed                 5               :            6 

time                   6               :            5

 ( Distance = Speed × Time , so ratio of speed and time is inverse to each other  ) 

According to question , ( 6 - 5 )R =  1R = 5 min 

Time taken with initial speed = 6 × 5 = 30 min