During period 5, 1,500 units of product X were made and the cost of grade Z labour was $17,500 for 3,080 hours. A unit of product X is expected to use 2 hours of grade Z labour at a standard cost of $5 per labour hour. During the period, however, there was a shortage of customer orders and 100 hours were recorded as idle time.

Required

Calculate the following variances.

(a) The labour total variance

(b) The labour rate variance

(c) The idle time variance

(d) The labour efficiency variance