Question

a bookseller makes the same percentage of profit on which sum he purchased a book by selling it for Rs.20.20. Find the cost price

Answer 1

The cost is "20.20"

Answer 2

Cost price are 17.23 rupees.

Step-by-step explanation:

1. Here it is given that

  Selling price (S.P)= 20.20

  Let cost price (C.P)= x

        Percentage of profit = x%

2. Selling price(S.P) = Cost Price (C.P) + Profit

   $\mathbf{20.20= x + \frac{x}{100}\times x}$

   $\mathbf{20.20= x + \frac{x^{2}}{100}}$

   $\mathbf{2020=100x+x^{2}}$

    $\mathbf{x^{2}+100x-2020=0}$      

    So

   $\mathbf{x=\frac{-100\mp \sqrt{\left ( 100^{2}-4\times 1\times (-2020) \right )}}{2}}$

  After solving above we get

 

  x= 17.32

 

  So cost price = 17.32 rupees

  and percentage of profit = 17.32%