In a recent survey of 400 students in a school, 100 were listed as smokers, 150 as chewers of gum, 75 were listed as both . Find out how many students where neither smokers nor chewers of gum

Afitness center has 2 membership plans one has a low dollar sign up fee of 15 dollars and costs 38 dollars per month to join. a second plan has a higher sign up fee of 78 dollars but a lower monthly fee of 31 dollars for what number of days of the month is the coat the same