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'.

Problem: two passenger trains start at the same hour in the day from two different stations and move towards each other at the rate of 12 kmph and 21 kmph respectively . when they meet , it is found that one train has traveled 60 km more than the other one . the distance between the two stations is ? 
Options: a ) 477 , b ) 396 , c ) 279 , d ) 276 , e ) 291
b

Problem: what is the least number of square tiles required to pave the floor of a room 11 m 50 cm long and 1 m 50 cm broad ? 
Options: a ) 724 , b ) 804 , c ) 69 , d ) 844 , e ) none
c

Problem: in one hour , a boat goes 11 km along the stream and 5 km against it . find the speed of the boat in still water 
Options: a ) 6 , b ) 7 , c ) 8 , d ) 9 , e ) 10

c