Preble Company manufactures one product. Its variable manufacturing overhead is applied to production based on direct labour$-$hours, and its standard costs per unit are as follows:

Direct materials: $5kg$ at $$8\mathrm{.}00$ per $kg=$ $$40$

Direct labour: $2$ hours $at$ $$14$ per hour $=28$

Variable overhead: $2$ hours $at$ $$5$ per hour $=10$

Total standard cost per unit $=$ $$78$

The company planned to produce and sell $25,000$ units in March. However, during March the company actually produced and sold $30,000$ units and incurred the following costs:

Purchased $160,000kg$ of raw materials at a cost of $$7\mathrm{.}50$ per kg$.$ All of this material was used in production.

Direct labour: $55,000$ hours at a rate of $$15\mathrm{.}00$ per hour.

Total variable manufacturing overhead for the month was $$280,500.$

Required:

$10-1$ What is the materials price variance for March?

$10-2$ What is the materials quantity variance for March?

$10-3$ If Preble had purchased $170,000kg$ of materials at $$7\mathrm{.}50$ per $kg$ and used $160,000kg$ in production, what would be the materials price variance for March?

$10-4$ If Preble had purchased $170,000kg$ of materials at $$7\mathrm{.}50$ per $kg$ and used $160,000kg$ in production, what would be the materials quantity variance for March?

$10-5$ What is the labour rate variance for March?

$10-6$ What is the labour efficiency variance for March?

$10-7$ What is the variable overhead spending variance for March?

$10-8$ What is the variable overhead efficiency variance for March?