Question

The Dubs division of Fast Company (the parent company) produces wheels for off-road sport vehicles. One-half of Dub's output is sold to the Hoon division of Fast; the remainder is sold to outside customers. Dub's estimated operating profit for the year is shown in the table.

	Internal Sales	External Sales	Totals
Sales	$300,000	$400,000	$700,000
Var Mfg.	$160,000	$160,000	$320,000
Var G&A	$40,000	$60,000	$100,000
CM	$100,000	$180,000	$280,000
Fixed Mfg.	$24,000	$32,000	$56,000
Fixed G&A	$36,000	$48,000	$84,000
Op. Profits	$40,000	$100,000	$140,000
Unit Sales	1,000	1,000	2,000

Unless otherwise stated assume the fixed costs given above are allocated costs and unavoidable. Hoon division has an opportunity to purchase 1,000 wheels of the same quality from an outside supplier on a continuing basis for $250.00 per wheel.

To simplify this example, assume the capacity of the Dubs division is 2,000 units and it is producing and selling units as shown in the table. If Dubs could sell all of its units in the external market at the current external selling price, by how much would Fast’s total contribution margin increase? Now also assume the Hoon division’s external supplier has raised its price to $325.00 per wheel. Indicate an increase with a positive number and a decrease with a negative number, e.g. -10000.

Answer 1

Hoon division
Purchase price from external suppliers	$              325
Purchase price from internal division (300000/1000)	$              300
Contribution margin lost per unit (for Hoon division)	$                 25
Multiply: Units for internal division	1,000
Contribution margin lost (for Hoon division)	$        25,000

Contribution margin per unit (180000/1000)	$              180
Multiply: Increase in external sales units	1,000
New contribution margin	$      180,000
Less: Contribution margin lost (for Hoon division)	$        25,000
Fast’s total contribution margin increase	$      155,000