Question

A shopkeeper earns a profit of $12\%$ on selling a book at $10\%$ discount on the marked price. The ratio of the cost price and the marked price of the book is

• A. $45:56$
• B. $45:51$
• C. $47:56$
• D. $47:51$

Answer 1

The correct option is A $45:56$

Let the C.P. be Rs. $x.$
Then, S.P. $=x+12\%$ of $x$
$\Rightarrow$ S.P. $=1.12x$
Let M.P. be Rs. $y.$
Then, $90\%$ of $y=1.12x$
$\Rightarrow \frac{90}{100}\times y=1.12x$
$\Rightarrow y=\frac{11.2x}{9}$

Now, required ratio $=x:\frac{11.2x}{9}$
$=9x:11.2x$
$=45:56$