If 15% of a number is subtracted from 30% of that number, the result is 45. The number is: MCQ with Answer and Explanation

Explanation:
Correct = 3x/5, wrong = 5x/3. Error % = [(5/3 - 3/5)/(3/5)]×100 = (16/9)×100 ≈ 177.78%.

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:
0.04 × 100 = 4%.