Hasak Corp makes 100 kg containers of vegetable seeds, and has the following unit standard costs for direct materials and direct labour:

Direct materials (80 kg @$2.00 per kg) $160.00

Direct labour (0.50 hours at $19.00 per hour) $9.50

Total standard costs per 100 kg container: $169.50

The following activities were recorded in June:

1. 1,800 containers were manufactured

2. 73,000 kg of materials costing $64,000 were purchased.

3. 99,000 kg of materials were used.

4. $13,000 was paid for 475 hours of direct labour.

There were neither beginning nor ending WIP inventories on hand. Required:

a) Compute the direct materials variances.

b) Compute the direct labour variances.

c) Suggest rational explanations for each variance.