Question

Joe purchased $20$ apples from a supermarket for $180$ rupees at a discount of $10$ percent. How much will a dozen apples cost him if he does not avail any discount?

• A. $Rs.108$
• B. $Rs.120$
• C. $Rs.132$
• D. $Rs.144$

Answer 1

The correct option is B $Rs.120$

Let the real cost of $20$ apples be $x.$

Joe purchased $20$ apples from a supermarket for $180$ rupees at a discount of $10$ percent.

$\therefore 90\%$ of $x=180$

$\Rightarrow \frac{90}{100}\times x=180$

$\Rightarrow \frac{9x}{10}=180$

$\Rightarrow x=\frac{10}{9}\times 180$

$\Rightarrow x=200$

$\therefore$ Real cost of 20 apples $=Rs.200$

$\Rightarrow$ Real cost of 1 apple $=\frac{200}{20}=Rs.10$

$\therefore$ Cost of a dozen apple $=10\times 12=Rs.120$

A dozen apple cost him Rs. $120$ if he does not avail any discount.