Vanny Ltd manufactures a product that requires 1.5 hours of machining. Machining time is a bottleneck resource, due to the limited number of machines available. There are 10 machines available, and each machine can be used for up to 40 hours per week. The product is sold for GH85 per unit and the direct material cost per unit is GH42.50. Total factory costs are GH8,000 each week. Calculate: (a) Return per factory hour (b) The Throughput Accounting Ratio (TPAR)