There is a total of 25 bicycles. if the ratio of gray bicycles to black bicycles is 6 to 9 how many of them are black?

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.

Jane moves from a house with 71 square feet of closet space to an apartment with 45.44 square feet of closet space. what is the percentage decrease of jane’s closet space?

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12