Trishul Industries is engaged in the manufacture of product 'Trishank". The prime cost details for which are as under: Cost per completed piece (Rs.) Component of Cost Details. Direct Materials Direct Labour 5 kgs @ Rs. 4.20/kg 3 hours @ Rs. 3/hr As per the production schedule, 5000 units were to be produced in December 2021. However, 5, 120 units were actually manufactured. Direct Materials were purchased to the tune of 30000 kgs and were billed at Rs. 1,35,000. The production records for the month of December 2021 were extracted and they showed the following results: Component of Cost Details Direct Materials Requisitioned and used - 25700 kgs Direct Labour 21.00 9.00 Worked and paid for - 15,150 hrs @ Rs. 48,480/- a) Calculate material cost variance, material usage variance and material price variance. (12 marks) b) Calculate labour cost variance, labour efficiency variance and labour rate variance (12 marks)