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'.
--------
Question: Problem: a man can row a distance of 5 km in 60 min with the help of the tide . the direction of the tide reverses with the same speed . now he travels a further 30 km in 10 hours . how much time he would have saved if the direction of tide has not changed ? 
Options: a ) 2 , b ) 8 , c ) 4 , d ) 6 , e ) 5

Answer: c


Question: Problem: a man is standing on a railway bridge which is 180 m long . he finds that a train crosses the bridge in 20 seconds but himself in 8 seconds . find the length of the train and its speed 
Options: a ) 50 km , b ) 52 km , c ) 54 km , d ) 56 km , e ) 58 km

Answer: c


Question: Problem: two trains of length 100 meters and 200 meters are 660 meters apart . they are moving towards each other on parallel tracks , at speeds of 90 km / h and 108 km / h . after how many seconds will the trains meet ? 
Options: a ) 12 , b ) 14 , c ) 16 , d ) 18 , e ) 20

Answer:
a