To get the original price we are going to; 
1) Subtract the discount percentage from 100 to get the original price percentage. 
100 - 25 = 75 % 
2) Now we are going to multiply the discounted price by 100. 
7500 x 100 = 750,000
3) Now we are going to divide the discounted price by the original price percentage. 
750,000 / 75 = 10,000
Therefore the original price is Rs 10,000