Given that, the price of medicine including 4% VAT is 36.40.
We have, selling price = cost price + VAT
⇒ Cost price = Selling price - VAT
⇒ The price before VAT was added = price including VAT – VAT
⇒ The price before VAT was added = 36.40 - 4/100 x 36.40
= 36.40 - 1.456
= Rs.34.944
= Rs.35