If C.P. of 26 books is equal to S.P of 30 books , then your gain or loss is ?	Answers:  A) 23 1/3 gain %  B) 30 10/23 loss %  C) 13 1/3 loss %  D) 30 1/3 loss %  E) 40 1/3 loss %
Say the cost price of 26 books is $26 so $1 for a book.   The cost of 30 books would be $30, and the selling price of 30 books would be 26$, hence the loss = ($30 - $26)/$30 = ~13.3%.   Answer: 13 1/3 loss %.
<result>C</result>
If C.P. of 26 books is equal to S.P of 30 books , then your gain or loss is ?