Sound waves are emitted from a fishing boat. Some of the sound waves are reflected by fish and detected back at the boat. The shortest time between the sound waves being emitted and detected is 0.26 s. The speed of sound in water is 1500 m/s. A) Calculate the distance between the boat and the nearest fish.

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

41/17 as a decimal rounded to the nearest hundredth

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.