A company developed the following per-unit standards for its product: 5 kilograms of direct materials at $3 per kilogram. Last month, 1,000 kilograms of direct materials were purchased for $2870. Also last month, 730 kilograms of direct materials were used to produce 143 units. What was the direct materials quantity variance for last month? $45 unfavourable $45 favourable $810 unfavourable $810 favourable