11.1 The Iris Company provides the following information relating to its variable overheads for October. Overheads are absorbed on the basis of labour hours:

Standard total variable overhead for October £800,000 Standard labour hours for October 80,000 Standard hours to produce 1 unit 5 Actual units produced in the first week of October 4,000 Actual labour hours in the first week of October 18,000 Calculate the variable overhead efficiency variance for Company F for the first week of October.