By a reduction of 20% in the price of oranges, one can purchase 5 oranges more for $\text{ ₹ }$ 2.50. Find the reduced price of the oranges per dozen and also the original price. 

Let original price be $\text{ ₹ }$ x per orange. Then. Reduced rate $=(1-0.2)x=₹0.8x$

$\therefore \frac{2.50}{0.8x}-\frac{2.50}{x}=5\Rightarrow \frac{25}{8x}-\frac{2.5}{x}=5\Rightarrow x=\frac{1}{8}$

$\therefore$ Original price of oranges per dozen $\frac{1}{8}\times 12=₹1.5$

and Reduced price $=₹\left(0.8\right)\left(1.5\right)=₹1.2$