Ravi can build a wall in same time in which Mahesh and Suresh together do it. If Ravi and Mahesh together do it in 10 days and Suresh alone in 15 days.In what time Mahesh do it alone?

P, Q, R are employed to do a work for Rs. 5750. P and Q together finished 19/23 of work and Q and R together finished 8/23 of work. Wage of Q, in rupees, is-

A can do a piece of work in 24 day, B in 32 days and C in 64 days. All begin to do it together, but A leaves after 6 days and B leaves 6 days before the completion of the work. How many days did the work last?