A work can be completed by P and Q in 12 and 16 days respectively. With the help of R they can complete the work in 6 days and earned Rs. 3696. Then find the share of R.

P completes work in 12 days, so rate = 1/12 per day. Q completes in 16 days, so rate = 1/16 per day. Together with R, they complete in 6 days. Combined rate = 1/6 per day. R's rate = 1/6 - 1/12 - 1/16 = (8 - 4 - 3)/48 = 1/48 per day. Earnings of Rs. 3696 are divided in ratio of their rates: (1/12) : (1/16) : (1/48) = 4 : 3 : 1. R's share = 3696 × 1/8 = 462.