Krivster manufacturing produces a premium health drink. The standard for one litre of the health drink for the month of May is as follows. Direct materials: 200gram @ $0.25 per gram Direct labour: 0.25 hours @ $22 per hour The following information relate to actual results for May. i. 22 000 litres were produced for the month of May ii. 4 150 000 grams were purchased @ $0.27 per gram iii. There was no opening or closing inventory of raw materials iv. 5000 labour hours were worked at a cost of $21.50 per hour What was the labour efficiency variance?