Develop Back-end System for E-commerce Site

PLEASE READ CAREFULLY AND FOLLOW INSTRUCTIONS We are looking to develop a complete e-commerce site. The key features of the site are: [login to view URL] -Products catalog, with images, views and information page. -Order Purchase/Funding system (Kickstarter model) -Payments system and gateways (multi country support) -User account system (user membership and data) Application requirements 1. Experience building similar systems and great technical skills 2. Please describe best technologies/tools to develop and how would you tackle each part/structure. 3. Time availability and time required to develop the system 4. Estimate on total hours and total cost required to build site 5. Please provide your answer to the following two brainteasers. Unorthodox but will let us see how you think. Method used in companies like Google, Facebook and others. i. How would you arrange 25 red balls and 65 blue balls into two different containers, so that when drawing one ball blind-folded from one of the containers, the probability of drawing a red ball is maximized? Calculate, What is the probability? ii. In semi-code how would you write a Mod (modulus) function that doesn't use the native mod function i.e. perhaps using any other methods, arithmetic, etc.