Question

Rakesh bought some chocolates at $10$ for $Rs1.50$ and an equal number at $20$ paisa each. He sold them at a rate of $20$ for $Rs4$ and made a profit of $Rs10$. How many chocolates did he purchase?

• A. $100$
• B. $200$
• C. $300$
• D. $400$

Answer 1

The correct option is B $200$

let $x$ chocolates be purchased

$10$ chocolates were bought at $Rsx1.50$

$\therefore$ cost price of $1$ chocolate $=Rsx\frac{1050}{10}$

$\therefore$ cost price $x$ chocolate $=Rsx0.15x$

cost price of auother $x$ chocolates $=Rs\frac{20}{100}x=Rsx0.2x$

$\therefore$ cost price $2x$ chocolate $=xRs(0.15x+0.2x)$

$=Rsx0.35x$

selling price of $20$ chocolates $=Rsx4.$

$\therefore$ selling price of $1$ chocolate $=Rs\frac{4}{20}=Rsx0.20$

$\therefore$ selling price $2x$ chocolates $Rsx0.4x.$

$\therefore$ profit wade on $2x$ chocolates $=Rsx(0.4x-0.35x)$

$=Rsx0.05x$

Given profit $=Rsx10.$

$\therefore 0.05x=10\Rightarrow \frac{5}{100}x=10\Rightarrow x=200$

$\therefore 200$ chocolates were purchased. answer