A shopkeeper gives a discount of 10% once in 4 months. If a man purchases an article in this scheme for Rs.25515 in December, then what was the initial price in January?

In a year there are three quarters over which the price has decreased. So you just have to assume the initial value to be "x". Then decrease it by 10% three times. That would be: x(0.9)(0.9)(0.9) x(0.9)^3 x( 0.729)=25515 x=35000