The parts can be purchased from an outside supplier for only $28 each. The space in which the parts are now produced would be idle and fixed production costs would be reduced by one-fourth. If the parts are purchased from the outside supplier, the annual impact on the company's operating income will be: a) $24,000 increase
b) $24,000 decrease
c) $56,000 increase
d) $56,000 decrease

d) $56,000 decrease

Explanation:

In the case when parts are produced by sharp corporation

Given that

Total cost per unit = $36

Total cost = Total cost per unit × parts

= $36 × 8,000

= $288,000

Now

If the parts are Purchased by the outside supplier, fixed costs decreased by one-fourth.

So, three-fourth fixed costs should be incurred.

Now  

Total cost per unit = Purchase Price + three - fourth fixed costs

= $28 + (3 ÷4) × $20

= $28 + $15

= $43

Now

Total cost = $43 × 8,000

= $344,000

So, the operating income is

= $288,000 - $344,000

= $56,000 decrease

answer; i believe the correct answer is (4.0);