From the following particulars, work out the earnings for the week of a worker under

  1. Straight piece rate
  2. Differential piece rate
  3. Halsey premium system
  4. Rowan system

Number of working hours per week = 48

Wage per hour = Rs. 3.75

Normal time per piece = 20 minutes

Rate per piece = Rs. 1.50

Normal output per week = 120 pieces

Actual output for the week = 150 pieces

Differential piece rate: 80% of piece rate when the output is below standard and 120% when above standard.