Time and Work Questions

One tap can fill a water tank in 50 mins and another tap can make the filled tank empty in 75 mins. If both the taps are open together, already half filled tank would be full in

S, T and U together can complete a work in 30 days. If the ratio of efficiency of S, T and U is 20 : 15 : 12 respectively, then in how many days U alone can complete the same work?

A is thrice as productive as C. Together they can complete a job in 22.5 days. If B joins them after they have worked for 15 days then in how many days can they finish the rest of the job if B alone can do the job in 15 days?

M is thrice as good as workman as N and together they finish a piece of work in 30 days. In how many days will M alone finish the work?

Prabhat has done 1/2 of a job in 12 days. Santosh completes the rest of the job in 6 days. In how many days can they together do the job?

Amar can complete a work in 30 days and Raman can complete the same work in 15 days. If both of them work together, then in 4 days what percent of the total work will be completed?

Pannalal has done 1/3rd of a job in 20 days, Saiprasad completes the rest of the job in 10 days. In how many days can they together do the job?

A, B and C can do a job working alone in 12, 16 and 24 days respectively. In how many days they can do the job if they worked together?