Gamma Corporation manufactures electronic gadgets. The standard direct material cost per unit is SAR 80, standard direct labor cost per unit is SAR 40, and standard variable overhead cost per unit is SAR 20. During August 2024, the company produced 800 units and incurred actual direct material costs of SAR 64,000, actual direct labor costs of SAR 32,000, and actual variable overhead costs of SAR 16,800. Calculate the direct material, direct labor, and variable overhead cost variances. Provide explanations for the variances and suggest possible actions for management.