US-retail giant Walmart and e-commerce firm Flipkart said they have made a joint strategic investment in Ninjacart, a startup which provides business-to-business (B2B) supply chain infrastructure and technology solutions. The three firms aim to help ensure better access to high-quality fresh produce for more retailers and consumers across India while also creating economic opportunities for farmers. The companies did not reveal the financial details of the transactions. This is the second strategic investment for Flipkart in the logistics segment this year, which is expected to help it take on Amazon's online grocery delivery business.Last week, Flipkart said it has made