Question

A 300 meters long train is travelling with the speed of 45 km/hr and it passes point A completely. At the same time, a motorbike starts from point A with the speed of 70 km/hr. When it exactly reaches the middle point of the train, the train increases its speed to 60 km/hr and motorbike reduces its speed to 65 km/hr. How much distance will the motorbike travel while passing the train completely ?
(a) 2.5 km
(b) 2.37 km
(c) 3.6 km
(d) 3.8 km
(e) None of these

Answer 1

Answer:

Step-by-step explanation:

Time taken by bike = 150/((70-45)*1000) + 150/((65-60)*1000) 70-45 and 65-60 are the relative speed of bike as train and bike are moving in the same direction and 1000 to convert m to km time = 6/(7*25) avg speed of bike will be 2*65*70/(65+70) then distance covered by bike will be 2*65*70/(65+70) * 6/(7*25) = 2.311 which close to 2.37 so, answer is B