Idris Furniture, Inc., sells lamps for $30. The unit variable cost per lamp is $22. Fixed costs total $9,600. Idris's tax rate is 40%. Required: a What is the contribution margin per lamp? b b. What is the contribution margin ratio for Idris Furniture, Inc. c What is the breakeven point in units and in dollars? d How many lamps must be sold to earn a pretax income of $8,000? e How many lamps must be sold to eam an after tax income of $6,000? f What is the margin of safety, assuming 1,500 lamps are sold? B What is the company's degree of operating leverage, assuming 1,500 larups are sold