Each unit of a certain product costs a manufacturer $9 to produce. The manufacturer sells the product in boxes of 50 units for $560 per box. How many boxes of the product does the manufacturer need to sell to yield a profit of $110,000 ?
(A) 90
(B) 100
(C) 900
(D) 1,000
(E) 1,100
鬼打牆~怎麼算都是不對
麻煩大大了