A worker takes 9 hours to complete a job on daily wages and 6 hours on a scheme of payment by results. His daily rate is Rs 7.50 per hour. The material cost of the product is Rs 40 and the overheads are recovered at 150% of the total direct wages. Calculate the factory cost of the product under

(a) piecework plan,

(b) Halsey’s plan and

(c) Rowan’s plan.