是毛利吗?
if A's gross profit=A's price-cost
B's gross profit=B's price-cost
then we are looking for (A's gross profit-B's gross profit)/B's goss profit
since the two costs are the same, then the above equation=(A's prcie-B's price)/B's price-cost
from 1) we know the relation between A's price and B's price but we don"t know cost and B's price, from 2) we only know the B's grossprofit, but no A"s or B's price, from 1)+2) we know price A and B's relation and B's grossprofit, and we need one of the exact price,
so the answer will be E
i don't know if the way i think is right! open for discussion
