a boy loses 20% by selling his old books for rs64 .find the cost price of the book​

1 thought on “a boy loses 20% by selling his old books for rs64 .find the cost price of the book​”

1. Answer :-

   The cost price of old books is Rs.80.

   Step-by-step explanation:

   To Find :-

   • The cost price of the book.

   ★ Solution

   Given that,

   • Loss percentage = 20%
   • Selling price of the book = Rs. 64

   Assumption :–

   Let us assume the cost price as Rs. x

   Loss = Rs. (20% of x)

   ⇒ (20/100 × x)

   ⇒ (2/10 × x)

   ⇒ Rs. x/5

   We know,

   Selling price = Cost price – Loss.

   Therefore,

   S.P. = C.P. – Loss = Rs. (x – x/5)

   ⇒ (x – x/5)

   ⇒ Rs. 4x/5

   Now, 4x/5 = 64

   ⇒ 4x/5 = 64

   ⇒ 4x = 64 × 5

   ⇒ 4x = 320

   ⇒ x = 320/4

   ⇒ x = 80

   Hence, The cost price Rs. 80.

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