These are the notations I'm gonna use,
Cost Price → P
Selling Price → P+∆P
Profit (or) Loss → ∆P
Relative Profit (or) Relative Loss →
Hence, Net Gain (or) Net Loss is .
Relative Net Gain.
Gain Percent is 1.714%.
Cost Price is 750 and Profit is 150.
3. Let 'P' be the price of article, then .
Hence, Cost Price (P) is 56.25.
Then Selling Price (P+∆P) is 67.5.
4. We have, .
Then, Cost Price (P) is 110.