A Co. manufacturing two products operates a standard costing system. The standard OH content of each produs in cost center 101 is Product A2.40 (8 direct labour hours @ 30 p. per hour) Product B 1.80 (6 direct labour hours @ 30 p. per hour) The rate of 30 p. per hour is arrived at as follows: Budgeted OH 570 Budgeted Direct labour Hours 1,900 Output of product A 100 units Output of product B 200 units No opening or closing stock Actual direct labour hours worked 2,320 Actual OH incurred 640 (a) you are required to calculate total OH for the month of October (b) Show division into: 1) expenditure 2) Volume 3) efficiency Variances