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'.

[EX Q]: 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
[EX A]: c

[EX Q]: Problem: john traveled 80 % of the way from yellow - town to green - fields by train at an average speed of 80 miles per hour . the rest of the way john traveled by car at an average speed of v miles per hour . if the average speed for the entire trip was 60 miles per hour , what is v in miles per hour ? 
Options: a ) 30 , b ) 40 , c ) 50 , d ) 55 , e ) 70
[EX A]: a

[EX Q]: Problem: a and b can complete a work in 15 days and 10 day . they started doing the work together but after 2 days b had to leave and a alone completed the remaining work . the whole work was completed in ? 
Options: a ) 10 days , b ) 12 days , c ) 15 days , d ) 8 days , e ) 16 days
[EX A]:
b