Each of 10 machines works at the same constant rate doing a certain job. the amount of time needed by the 10 machines, working together, to complete the job is 16 hours. how many hours would be needed if only 8 of the machines, working together, were used to complete the job?

What do supreme court decisions based on the first amendment usually involve?

Adolescents can display egocentrism when they become about changes in their lives.

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling