Put your quant hat on! In the main text, it is claimed, If the gross margin of a product was 30%, it could be increased as much as 17% through simply raising the price 5% if the cost is not changed. Explain this mathematically.

Tsukakoshi believes that as long as a company is confident in its products competitiveness, there are always methods to raise prices and increase profits smoothly. Is this a viable general business model in a deflationary environment?

The case authors consider Ina Foods successful price increase in a period of deflation to be a contrarian strategy. What is a contrarian strategy? What in the case supports Ina Foods contrarian strategy?