Biologists tagged 75 fish in a lake on January 1. On February 1, they returned and collected a random sample of 30 fish, 10 of which had been
previously tagged. On the basis of this experiment, approximately how
many fish does the lake have?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ab=9, and ac=12, find hc.

Which graph represents the solution set for the given system of inequalities? x+2y< 3 x+y> 4 3x-2y> 4

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?