Question

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

Answer 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.