The owner of a luxury motor yacht that sails among the 4000 Greek islands charges $460 per person per day if exactly 20 people s
ign up for the cruise. However, if more than 20 people (up to the maximum capacity of 90) sign up for the cruise, then each fare is reduced by $7 per day for each additional passenger. Assume at least 20 people sign up for the cruise, and let x denote the number of passengers above 20. (a) Find a function R giving the revenue per day realized from the charter. R(x)