### A dealer allows his customer a discount of 25% and still gains 25%. If cost price of a radio is Rs. 1440, its marked price is:

A. Rs. 2500 B. Rs. 2440 C. Rs. 2400 D. Rs. 2020 Answer: Option C
Let MP = X CP = 1440 SP = 1440 + 25% of 1440 = Rs. 1800 SP = MP – 25% of MP SP = X – 25% of 100 SP = X – 0.25X 1800 = 0.75X X = 2400 MP = Rs. 2400 Short-Cut Let the marked price = Rs. x Hence, $\begin{array}{l}\frac{75\times\mathrm{x}}{100}=1440\times\frac{125}{100}\\ \Rightarrow\frac{1440\times125}{75}=Rs.2400\end{array}$