Lindin Inc, produces key ingredient for liquid laundry detergents. Two chemical solutions, A and B, are mixed and heated to produce a cleansing chemical that is sold to companies that produce the liquid detergents. The cleansing ingredient is produced in batches and has the following standards: Yield should amount to 15000 litres. During March, the following actual production information was provided: Required: 3.1 Calculate the direct materials mix and yield variances. 3.2 Calculate the total direct materials usage variance for A and B. Show that the total direct materials usage variance is equal to the sum of direct materials mix and yield variances