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 boat running downstream covers a distance of 12 km in 2 hours while for covering the same distance upstream , it takes 3 hours . what is the speed of the boat in still water ? 
Options: a ) 8 kmph , b ) 5 kmph , c ) 4 kmph , d ) 6 kmph , e ) 7 kmph
b

Problem: james took a 3 - hour bike ride . in the second hour he traveled 30 miles , which was 20 percent farther than he traveled the first hour . if he traveled 25 percent farther in the third hour than he did in the second hour , how many miles did jose travel during the entire ride ? 
Options: a ) 54.0 , b ) 54.9 , c ) 92.5 , d ) 57.0 , e ) 63.0
c

Problem: 20 men do a work in 20 days . how many men are needed to finish the work in 10 days ? 
Options: a ) 50 , b ) 20 , c ) 30 , d ) 10 , e ) 40

e