A shopkeeper mixes 3 litres of water with 15 litres of milk costing Tk 60 per litre and sells the whole at cost price. What is the profit percentage?

Question: A shopkeeper mixes 3 litres of water with 15 litres of milk costing Tk 60 per litre and sells the whole at cost price. What is the profit percentage?

Solution:
→ Total cost = 15 × 60 = Tk 900
→ Total volume = 18 litres, Selling price per litre = 900/18 = Tk 50
→ Profit per litre = 60 – 50 = Tk 10
→ Profit % = (10/50)×100 = 20%