The C.P of 10 pens is equal to the S.P of 13 pens. Find his gain % or loss%?  Choose the most appropriate option
A) loss 16 2/8% B) loss 16 6/3% C) loss 23.08% D) loss 18 2/3% E) loss 16 25%
10 loss 23.08%P = 13 SP   13 --- 3 loss 23.08%P loss   100 --- ? =&gt; 23.08% loss   Answer:loss 23.08%
<result>C</result>
The C.P of 10 pens is equal to the S.P of 13 pens. Find his gain % or loss%?