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: a garrison of 2000 men has provisions for 54 days . at the end of 15 days , a reinforcement arrives , and it is now found that the provisions will last only for 30 days more . what is the reinforcement ? 
Options: a ) 1800 men , b ) 3900 men , c ) 600 men , d ) 3800 men , e ) 900 men
c

Problem: a train 300 m long takes 9 sec to cross a man walking at 3 kmph in a direction opposite to that of the train . find the speed of the train ? 
Options: a ) 100 kmph , b ) 90 kmph , c ) 120 kmph , d ) 117 kmph , e ) 125 kmph
d

Problem: mike took a bus from home to market , that travels at 30 kmph . while walking back at 6 kmph , halfway through , he suddenly realized he was getting late and he cycled back the remaining distance in 20 kmph . find the average speed . 
Options: a ) 21.2 kmph , b ) 12.1 kmph , c ) 23.4 kmph , d ) 20.4 kmph , e ) none of these

a