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 , b and c can complete a piece of work in 24 , 6 and 12 days respectively . working together , they will complete the same work in : 
Options: a ) 33 / 7 , b ) 43 / 7 , c ) 24 / 7 , d ) 19 / 7 , e ) none
c

Problem: a can do a work in 24 days and b can do it in 8 days . in how many days a and b can do the work ? 
Options: a ) 20 days , b ) 10 days , c ) 6 days , d ) 8 days , e ) 7 days
c

Problem: a can finish a work in 21 days and b can do the same work in 15 days . b worked for 10 days and left the job . in how many days , a alone can finish the remaining work ? 
Options: a ) 6 , b ) 5 , c ) 5.5 , d ) 7 , e ) 8

d