What will be the labour cost variance

13) In a factory 100 workers are engaged and the average rate of wages is Rs.5/. per hour. Standard working hours per week are 40 and the standard performance is 10 units per gang hour. During a week in April, 2005 wages paid for 50 workers were R35 per hour, 10 workers at Rs.3.50 per hour and 40 workers at Rs.5.20 per hour. Actual output was 380 units. The factory did not work for 5 hours due to breakdown of machinery. Calculate: a) Labour Cost Variance b) Labour Rate Variance 0) Labour Efficiency Variance of) Labour Yield Variance e) Idle Time Variance