A dishonest shopkeeper uses 800 g weight instead of 1 kg. His profit %: MCQ with Answer and Explanation

Explanation:
CP per g = 1, SP per g = 1.1. For 800 g, CP=800, SP=1000×1.1? Actually, he sells 800 g as 1 kg, so SP for 800 g = price of 1 kg at 10% profit = 1.1 times CP of 1 kg. Let CP of 1 kg = 1000, SP=1100. But he gives only 800 g, so CP=800, SP=1100. Profit = 300, % = (300/800)×100 = 37.5%.

Explanation:
50% = 5000, total = 10000.

Explanation:
1.1 × 0.9 = 0.99, 1% decrease.