CA CPT Dec 2015 Question Paper Fundamentals of Accounting for online practice

A purchase goods worth Rs. 1,50,000 out of which his sold goods worth Rs. 80,000 for Rs. 1,00,000. Costof remaining stock is Rs. 70,000 and the market value of the remaining stock is Rs. 85,000. He value thestock at market price. Which of following concept has been violated by him.