Exercise $6\mathrm{.}3\mathrm{.}1$ : Write the following SQL queries, based on the database schema Product$($maker$,$ model, type$)$ PC$($model$,$ speed, ram, hd$,$ price$)$ Laptop$($model$,$ speed, ram, hd$,$ screen, price$)$ Printer$($model$,$ color, type, price$)$ a$)$ Find the makers of PC $$s with a speed of at least $3\mathrm{.}0.$ b$)$ Find the printers with the highest price. c$)$ Find the laptops whose speed is slower than that of any PC