If the selling price of a product is multiplied by 2, then the resultant profit is 6 times the original profit. What is the original profit percentage?

Let's assume the initial selling price and cost prices are 'SP' and 'CP' respectively.

Let's assume the initial profit is 'P'.

SP-CP = P    Eq.(i)

If the selling price of a product is multiplied by 2, then the resultant profit is 6 times the original profit.

2SP-CP = 6P    Eq.(ii)

Eq.(i) is subtracted from Eq.(ii).

2SP-CP-(SP-CP) = 6P-P

2SP-SP = 5P

SP = 5P    Eq.(iii)

Put Eq.(iii) in Eq.(i).

5P-CP = P

5P-P = CP

CP = 4P    Eq.(iv)

Original profit percentage = $$\frac{P}{CP}\times\ 100$$

Put Eq.(iv) in the above equation.

= $$\frac{P}{4P}\times\ 100$$

= 25%