P and Q can complete a work in 30 days and 45 days,

Solution

Let the total work be LCM of (30, 45 and 15) = 90 units Number of units of work done by P alone in one day = 90/30 = 3 units Number of units of work done by Q alone in one day = 90/30 = 2 units Number of units of work done by P, Q and R together in one day = 90/15 = 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 = 90/1 = 90 days So, per day wage of R = 5400/90 = Rs. 60