Which expression represents the number of possible permutations of n items taken r at a time?

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.

18 16 11 45 33 11 33 14 18 11 what is the mode for this data set

The function f(x)= x5+ ( x + 3)2 is used to create a table. if x = -1 then what is f(x)?