How do I know what the mean or Median is ?

Autility company burns coal to generate electricity. the cost c(p), (in dollars) of removing p percent of the some stack pollutants is given by c(p)= 85000p/100-p a) find the cost to remove 30% of the pollutant b) find where the function is undefined

Julia chooses a card at random from her set of cards. what is the probability that the card is labeled cat or hamster?

Which point on the x-axis lies on the line that passes through point c and is parallel to lino ab?