Selected operating information on three different companies for a recent year is given below:

		Company
	A	B	C
Full-capacity machine-hours	10,000	18,000	20,000
Budgeted machine-hours*	9,000	17,000	20,000
Actual machine-hours	9,000	17,800	19,000
Standard machine-hours allowed for actual production
	9,500	16,000	20,000
*Denominator activity for computing the predetermined overhead  rate.

Required:

For each company, state whether the company would have a favorable or unfavorable volume variance and why.