Gumchara Corporation reported the following information with respect to the materials required to manufacture amalgam florostats during the current month:

Standard price per gram of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $4

Standard quantity of materials per amalgam florostat . . . . . . . . . . . . . . . . . . . . . 5 grams

Actual materials purchased and used in production . . . . . . . . . . . . . . . . . . . . . . . 6,000 grams

Actual amalgam florostats produced during the month . . . . . . . . . . . . . . . . . . . . 1,000 units

Actual cost of materials purchased . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $18,000

Normal monthly output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 units

a. Determine Gumcharas materials price variance.
b. Determine Gumcharas materials quantity variance.
c. Will Gumcharas overhead volume variance be favorable or unfavorable? Why?