In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Let me give you an example: Problem: walking at 5 / 6 th of its usual speed a cab is 15 mnts late . find its usual time to cover the journey ? 
Options: a ) 25 m , b ) 45 m , c ) 32 m , d ) 75 m , e ) 62 m
The answer to this example can be: d
Here is why: New speed = 5 / 6 th of usual speed new time = 6 / 5 th of usual time 6 / 5 ut - ut = 15 m ut / 5 = 15 m ut = 75 m answer is d

OK. solve this:
Problem: a train is 700 meter long is running at a speed of 21 km / hour . in what time will it pass a bridge of 130 meter length ? 
Options: a ) 142.286 , b ) 251.228 , c ) 34 , d ) 200 , e ) 150.627
Answer:
a