The C.P of 15 books is equal to the S.P of 18 books. Find his gain% or loss%?	Choose the correct choice from the following answers.
A) 16 2/3%	B) 16 2/7%	C) 16 7/3%	D) 18 2/3%	E) 11 2/3%
15 CP = 18 SP   18 --- 3 CP loss   100 --- ? =&gt; 16 2/3% loss   16 2/3%nswer: 16 2/3%
<result>A</result>
The C.P of 15 books is equal to the S.P of 18 books. Find his gain% or loss%?