I was given the following problem in my Business Combinations class and given the answer.

I was given the following problem in my Business Combinations class and given the answer. However, can you please show me how they worked out that answerX-Beams Inc. owned 70% of the voting common stock of Kent Corp. During 2011, Kent made several sales of inventory to X-Beams. The total selling price was $180,000 and the cost was $100,000. At the end of the year, 20% of the goods were still in X-Beams' inventory. Kent's reported net income was $300,000. What was the noncontrolling interest in Kent's net income? ANSWER IS BA. $90,000.B. $85,200.C. $54,000.D. $94,800.E. $86,640.