By selling an article for ₹640, a person loses 15% of its selling price. At what price (in ₹) should he sell it to gain 15% on its cost price?

846.40

Selling price = 640

Loss on selling price = 15% =  \(\frac{3x}{20x}\) = \(\frac{Loss}{SP}\)

CP = 20x + 3x = 23x

CP = 20x = 640 (Given)

1x = 32

Req. SP to gain 15% on CP = 115% of 23x = 26.45x

1x = 32

26.45x = 846.4