1. A database schema consists of four relations, whose schemas are: Product (maker, model, type) PC(model, speed, ram, hd, price) Laptop (model, speed, ram, hd, screen, price) Printer(model, color, type, price) The Product relation gives the manufacturer, model number, and type (PC, laptop, or printer) of various products, assuming that model numbers are unique over all manufacturers and product types. The PC relation for each PC gives the model number, the processor speed, the size of RAM (in MG), the size of hard disk (in GB), and the price. The Laptop relation is similar, but also giving the screen size (in inches). The Printer relation records for each printer model whether the printer produces color output (true, if so), the process type (e.g., laser or ink-jet), and the price. Based on these relations, draw expression trees for the following queries. a) What PC models have a speed of at least 3.00? b) Which manufacturers make laptops with a hard disk of size at least 100GB? c) Find the model number and price of all products (of any type) made by manufacterer B d) Find the model numbers of all color laser printers e) Find those manufacturers that sell Laptops, but not PC's