Time and Work Questions

Parimal has done 1/4th of a job in 10 days, Salim completes the rest of the job in 20 days. In how many days can they together do the job?

A can do a work in 36 days and B in 12 days. If they work on it together for 3 days, then what fraction of work is left?

A and B can together complete a task in 18 hours. After 6 hours A leaves. B takes 36 hours to finish rest of the task. How many hours would A have taken to do the task if he worked alone?

Mahanath works 2 times as fast as Sahay. If Sahay can complete a job alone in 21 days, then in how many days can they together finish the job?

A  field  can  be  reaped  by  12  men  or  18  women  in  14  days.  In  how  many  days  can  8  men  and  16 women reap it?

Sumit is 28% less efficient than Amit. If Amit can make a wall in 54 days, then Sumit can complete the same work in how many days?

A can do 75% of a job in 9 days and B can do half of the job in 8 days. If they work on it together, then in how many days can they do half of the job?

A can complete a task alone in 8 days, while B takes 12 days to do it by herself. Together with C it takes them 4 days to complete the work. If C and D together can complete the task in 15 days, then how many days will D need to complete the task by herself?