From the following particulars you are required to work out the earnings of a worker for a week under (a) Straight piece rate, (b) Differential piece- rate, (c) Halsey premium scheme (50% sharing), and (d) Rowan premium scheme. Weekly working hours 48 Normal time taken per piccc 20 minutes Hourly wage rate Rs. 7.50 Normal output per week Piece rate per unit Rs. 3.00 Actual output for the week Differential piece rate 80% of piece-rate when output below normal and 120% of piece-rate when output above normal. (I.C.W.A. Inter, December 1989) 120 pieces 150 pieces