Please assist with the below question. I provided my answers which were wrong. Would like to figure out where I went wrong.

ABC Company manufactures an electronic device. Last year, the per-unit product cost was $60, the per-unit prime cost was $38, and the per-unit conversion cost was $45. Cost of goods sold for the year was $600,000 and the sale price per unit was $110. In addition, direct labor costs of $210,000 and selling and administrative expenses of $250,000 were incurred.

Required:

A. Calculate how many units were sold last year

600,000/45+38

600,000/83=7,228.915

7,228 units were sold last year

B. Compute the cost of direct materials used

Total units sold per year * 60= cost of direct materials used

7,228*60=$433,680.00

C. Compute the cost of overhead

Direct labor costs +selling and administrative expenses

210,000+250,000=460,000

D. Compute the gross margin for the year

7,228*110=795,080

795,080-460,000=335,080

E. Calculate operating income

(7,228 * $110)-($600,000+210,000+250,000)

795,080-1,060,000

[(110)*(7,228)-($45)*(7,228)]-($60)=5,746,512,920

[795,080-325,260]

459,820-60=469,760