In the class of 40 students,18 passed mathematics,19 passed account,16 passed economics,5 passed mathematics and accounts only ,2 passed accounts and economics only. if each student offered at least one of the subject a: how many students failed in all the subjects
b: find the percentage number who failed in at least one of economics and mathematics
C: calculate the probability that a student selected at random failed in accounts..

When are two distinct non vertical lines parallel

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.

The length of each stair is 11 inches. what is the rise, r, for each stair? round to the nearest inch. 2 inches 7 inches 17 inches 24 inches