Asmall class has 10 students, 4 of whom are girls and 6 of whom are boys. the teacher is going to choose two of the students at random. what probability that the teacher will choose two boys?

See attachment below and find the equivalent of tan(∠qsr)

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?

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.