Ruby is visiting San Francisco. From her hotel she walks 2 blocks east an 4 blocks north to a coffee shop. Then she walks 4 blocks west and 3 blocks north to a museum. Where is the museum in relation to her hotel?PLEASE HELP FAST

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25

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.