Question

A bookseller sells 84 books at the cost of 72 books. Find his profit or loss%
A.14.28% B. 28.24% C. 20.4% D. 12.86%
Ans :

Answer 1

$\sf \purple{let}$

$\sf price \: of \: a \: book \: be \: \red {\bf x}$

$\implies \sf cost \: of \: 84 \: books (cost \: price)= 84\it x$

$\implies \sf cost \: of \: 72 \: books(selling \: price) = 72 \it x$

$\blue{ \boxed{ \tt loss = cost \: price - selling \: price}}$

$\implies \sf loss = 84 \it x \: \sf - 72 \it x$

$\therefore \sf loss = 12\it x$

$\blue { \boxed{ \tt loss \: \% = \frac{loss}{cost \: price} \times 100}}$

$\implies \sf loss \: \% = \frac{12 \it x}{84 \it x} \times 100$

$\implies \sf loss \: \% = \frac{12 \it }{84 \it } \times 100$

$\implies \sf loss \: \% = 0.1428 \times 100$

$\orange{\therefore \sf loss \: \% = 14.28\% }$

HOPE IT HELPS!

Answer 2

Given: A bookseller sells 84 books at the cost of 72 books.

To find: profit or loss percent

Solution: Let us assume the cost price of one book as C,

and the selling price of one book as S.

According to the question,

84S = 72C

⇒ S = 72C/84

⇒ S = 6C/7

Since S is smaller than C,

hence loss percent = ((C - S) X 100)/C percent

                                 = ((C - 6C/7) X 100)/C percent

                                 = (C/7 X100)/C percent

                                 = 100/7 percent

                                 = 14.28 percent

Answer: The correct option is A. 14.28 percent.