Who discovered the golden ration and when

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

Mike wants to make meatloaf. his recipe uses a total of 8 pounds of meat. if he uses a 3 to 1 ratio of beef to pork, how much pork will he use? enter your answer as a mixed number in simplest terms.

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?