Sugar-free gum contains 40% less calories than regular gum. if a piece of regular gum contains 40 calories , how many calories does a piece of sugar-free gum contain?

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.

How many ordered pairs of positive integers satisfy xy=32?

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.