Question

by selling 8 dozen pencils a shopkeeper gains the selling price of one dozen pencils.find the gain percent

plz give me the answer showing proper steps

Answer 1

Let CP of 1 pencil=x and SP=y
8y=12x
y=12/8 x
  = 1.5 x
P=SP-CP
   =1.5x-x
   = 0.5x
P%=P/CP * 100
      = 0.5x/x * 100
      = 50%