Question

A person bought two clocks. The cost price of one of them exceeds by $\frac{1}{4}$ the price of the other. He sold the costlier clock to the dealer at a gain of $10\%$ and the other at a gain of $7.5\%$ and thus got $Rs98$ in all as $SP.$ Find the total cost price of two clocks

• A. $Rs.150$
• B. $Rs.90$
• C. $Rs.75$
• D. $Rs.100$

Answer 1

The correct option is B $Rs.90$

Let the cost of clock-$1=x$ when $x$ is in Rs.

Then the cost price of clock $-2=x+\frac{x}{4}=\frac{5x}{4}$.

So the sell price of clock-2 at 10% profit=$\frac{5x}{4}(1+\frac{10}{100})=\frac{11x}{8}$ and

the sell price of clock-1 at 7.5% profit=$x(1+\frac{7.5}{100})=\frac{43x}{40}$.

So the total sell price=$x(1+\frac{7.5}{100})=\frac{43x}{40}+\frac{11x}{8}\frac{98x}{40}$.

But the total sell price=Rs98.

$\therefore \frac{98x}{40}=98⟹x=Rs40.\therefore \frac{5x}{4}=\frac{5\times 40}{4}=Rs50.$

so the total sell price $=Rs(40+50)=Rs90$.