Time and Work Questions

45 men or 60 boys can do a piece of work in 20 days. How many days will 15 men and 20 boys take to complete the work?

3 men or 4 women can complete a job in 120 days. 12 men and 16 women will complete the same job in how many days?

A can do a certain job in 12 days. B is 60% more efficient than A. Then B can do the same piece of work in

A and B together can do a piece of work in 9 days. If A does thrice the work of B in a given time, the time A alone will take to finish the work is

In a computer game, there are builders and destroyers. Together there are 20 of them. Some of them try to build a wall around a castle while the rest try to demolish it. Each of the builders can build the wall alone in 15 hours while any of the destroyers can demolish it in 10 hours. If all 20 builders and destroyers are made active when there is no wall and the wall gets built in 3 hours, how many of them are destroyers?

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

A, B and C can together do a job in 9 days. C alone can do the job in 36 days. In how many days can A and B do 50% of the job working together?

A can finish a work in 18 days and B in 36 days. If they work on it together for 9 days, then what percent of work is left?