Easy 15 points
in july 2013, the spacecraft messenger was near mercury at a distance of 9.75 × 10^7 km from earth.
taking the speed of light to be 3 × 10^8 m/s,

(a) work out how long it takes light to travel a distance of 9.75 × 10^7 km.
plz answer as quickly as possible.

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.