Somehow the idea of Preev+5% seems to be unclear.
Lets say bitcoin is 50,000 on Preev. I will pay 50,000+5% so 50,000*1.05 = 52,500
If I pay 52,500 I get 1 bitcoin.
If I pay half I pay 26250 I get 26250/52,500 = .5 bitcoin.
If I pay 5250 I get 5250/52500 bitcoin = .1
If I pay 5000 I get 5000/52500 bitcoin = .0952381
This all will seem obvious, but how can you use Preev to make the math simple?
When I pay 52500 I am paying 5% extra on the price of Bitcoin. So even though I am paying 52500 I am getting 1 bitcoin only.
This means that for the price of 1.05 bitcoin I am getting 1 bitcoin.
If you use preev to add 5% you have to increase the bitcoin amount to 1.05 thats the selling rate in rupees for 1 bitcoin. Then you take out your calculator and divide 5000 by the selling rate to get the fractional bitcoin amount.