The function c(w) = 0.013w^2 - w - 7 estimates the wind chill temperature c(w) at 0f for wind speeds w from 5 to 30 miles per hour. estimate the wind chill temperature at 0f if the wind speed is 20 miles per hour

Dr. cooper just started an experiment. he will collect data for 8 days. how many hours is this

Nine more than four times a number is the same as one less than twice the number. find the number?

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.