P and Q can complete a work in 26 days and 39 days,

Solution

Let the total work be LCM of (26, 39 and 13) = 78 units Number of units of work done by P alone in one day = 78/26 = 3 units Number of units of work done by Q alone in one day = 78/39 = 2 units Number of units of work done by P, Q and R together in one day = 78/13 = 6 units Number of units of work done by R alone in one day = 6 – 3 – 2 = 1 unit So, time taken by R alone to complete the work = 78/1 = 78 days So, per day wage of R = 5850/78 = Rs. 75