Imperial Motors expected to service 500 vehicles during the month of May. Servicing each vehicle reqires 3 hours of labour. The company actually used 1 518 hours of labour to service 460 vehicles. The labour efficiency variance was R 3 105 (unfavourable) 4.2.1. Calculate the standard labour rate per hour 4.2.2. Explain how a favourable direct labour rate variance may be interrelated with an unfavouravle direct labour efficiency variable