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Judith is standing on a balcony of a building. the height of the building is 20 meters high. she throws a ball at a velocity of 15 meters per second. how many seconds will it take for the ball to hit the ground? ( assume gravity is 9.8 meters per second squared.

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i

One file clerk can file 10 folders per minute. a second file clerk can file 11 folders per minute. how many minutes would the two clerks together take to file 672 folders?