CA CPT 2016 June Question Paper Fundamentals of Accounting for online practice

Sohan purchased goods for Rs.18,00,000 and sold 4/5th of the goods for Rs.21,60,000 andmet expenses amounting to Rs.3,00,000 during the year, 2015. He counted net profit asRs.4,20,000. Which of the accounting concepts was followed by him?