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: a can do a piece of work in 4 hours ; b and c together can do it in 3 hours , which a and c together can do it in 2 hours . how long will b alone take to do it ? 
Options: a ) 15 hours , b ) 14 hours , c ) 12 hours , d ) 74 hours , e ) 79 hours
[EX A]: c

[EX Q]: Problem: along a yard 414 metres long , 24 trees are palnted at equal distances , one tree being at each end of the yard . what is the distance between two consecutive trees 
Options: a ) 18 , b ) 19 , c ) 10 , d ) 11 , e ) 12
[EX A]: a

[EX Q]: Problem: if i walk at 6 km / h , i miss the bus by 12 minutes . if i walk at 5 km / h , i reach 14 minutes before the arrival of the bus . how far i walk to reach the bus stand ? 
Options: a ) 13 km , b ) 12 km , c ) 11 km , d ) 6.5 km , e ) 5.5 km
[EX A]:
a