If a commission of 10% is given on the marked price of a book, the publisher gains 20%. If the commission is increased to 15%, the gain is ______.
(A) 
(B) 
(C) 
(D) None of these
If a commission of 10% is given on the marked price of a book, the publisher gains 20%. If the commission is increased to 15%, the gain is ______.
(A)
(B)
(C)
(D) None of these