If 12 types only last 4 days, and the rest last an average of 6, then the average amount of days that ALL the flowers wilt would be 5. To find the average, you add 6 and 4 to get 10, and since there is only 2 number we added togehter to get 10, you would divide 10 by 2 to get 5!
Let s be the side length of the square. The dimensions of the rectangle are three times the side of the square (i.e. 3s), and two less than the side of the square (i.e. s-2).
So, the area of this rectangle is

The area of the square is
, and we know that the two areas are the same, so we have

The solution s=0 would lead to the extreme case where the rectangle and the square are actually a point, so we accept the solution s=3.
Answer:
22.5 i think should be your answer