Slick Corporation is a small producer of synthetic motor oil. During May, the company produced 5,000 cases of lubricant. Each case contains twelve quarts of synthetic oil. To achieve this level of production, Slick purchased and used 16,500 gallons of direct materials at a cost of $20,307. It also incurred average direct labor costs of $15 per hour for the 3,896 hours worked in May by its production personnel. Manufacturing overhead for the month totaled $9,153, of which $2,200 was considered fixed. Slick's standard cost information for each case of synthetic motor oil is as follows:

Direct materials standard price $ 1.30 per gallon
Standard quantity allowed per case 3.25 gallons
Direct labor standard rate $ 16 per hour
Standard hours allowed per case 0.75 direct labor hours
Fixed overhead budgeted $ 2,600 per month
Normal level of production 5,200 cases per month
Variable overhead application rate $ 1.50 per case
Fixed overhead application rate ($2,600 ÷ 5,200 cases) 0.50 per case

Total overhead application rate $ 2.00 per case

a.  Compute the materials price and quantity variances.