The standard factory overhead rate is $12 per machine hour ($10 for variable factory overhead and $2 for fixed factory overhead) based on 100% capacity of 42,000 machine hours. The standard cost and the actual cost of factory overhead for the production of 2,000 units were as follows:

Actual: Variable factory overhead	$350,500
Fixed factory overhead	84,000
Standard: 35,000 hours @ $12	420,000

Determine the (a) volume variance, (b) controllable variance, and (c) total factory overhead cost variance.

a. Volume variance	$
b. Controllable variance	$
c. Total factory overhead cost variance	$