A shopkeeper mixed low-quality vegetable oil costing Tk. 40 per litre with sunflower refined oil costing Tk. 80 per litre in a ratio of 2 ∶ 3 respectively. If he sold the mixture at Tk. 100 per litre, find his profit percentage.

Solution: A shopkeeper mixed low-quality vegetable oil costing Tk. 40 per litre with sunflower refined oil costing Tk. 80 per litre in a ratio of 2 ∶ 3 respectively. If he sold the mixture at Tk. 100 per litre, find his profit percentage.

Solution:
Let,
Quantity of low-quality vegetable oil in mixure 2x litre.
∴ The costing price of low-quality vegetable oil Tk. (40 × 2x) = Tk. 80x

Quantity of sunflower refined oil in mixure 3x litre.
∴ The costing price of sunflower refined oil Tk. (80 × 3x) = Tk. 240x

∴ Total costing price = Tk. (80x + 240x) = Tk. 320x

Total selling price = Tk. (100 × 5x) = Tk. 500x

∴ Profit = Tk. (500 - 320) = Tk. 180

∴ Profit percentage = (180/320) × 100%
= 56.25%