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: ram , who is half as efficient as krish , will take 27 days to complete a task if he worked alone . if ram and krish worked together , how long will they take to complete the task ? 
Options: a ) 16 days , b ) 12 days , c ) 9 days , d ) 6 days , e ) 18 days
c

Problem: a courtyard is 25 meter long and 16 meter board is to be paved with bricks of dimensions 20 cm by 10 cm . the total number of bricks required is 
Options: a ) 16000 , b ) 18000 , c ) 20000 , d ) 22000 , e ) 24000
c

Problem: 8 men can do a piece of work in 12 days . 4 women can do it in 48 days and 10 children can do it in 24 days . in how many days can 10 men , 4 women and 18 children together complete the piece of work ? 
Options: a ) 5 days , b ) 15 days , c ) 28 days , d ) 6 days , e ) 7 days

a