Zamra company sell its product for $15 per unit (selling 20,000 units). Last year the company reported total variable expenses of $180,000, fixed expenses of $90,000, and a net operating income of $30,000. The sales manager proposed some adjustments, 15% increase in the selling price and the reduce in unit sales by 10%. If the proposed changes are adopted, net operating income would: increase by $45,000 .a increase by $37,500 .b increase by $7,500 .c increase by $28,500 .d Which of the following statements regarding variable costs is incorrect? .a Variable costs on a per unit basis will decrease with increases in activity. .b Variable cost per unit is constant with the decrease in activity. Total variable costs will increase with the increase in activity. .d Total variable costs will decrease with the decrease in .activity