P, Q and R Ratio of monthly equivalent= (10 x 20) : (30 x 8) : (16 x 9)= 200 : 240 : 144 = 25 : 30 : 18Hence R's share = [18/(25 + 30 + 18)] x 2920= (18/73) x 2920 = 18 x 40 = 720