When there are a Global variable and Local variable with the same name, how will you access the global variable?

What is the key difference between a variable that is used just once and a static variable?

write a C++program that finds the total amount to be spent on a vacation. In Main ask the user for the number of days for the trip and the name of the person booking the trip. It should then call FindHotelCost() and pass both of these variables to that function. The FindHotelCost() function should give a message using the persons name who is booking the trip with the hotel bill. The bill will be 550 dollars for each day of the trip. It should then call AddRentalCar() and pass the name and number of days and the hotel bill to that function AddRentalCar() asks the user for the number of miles that were driven on the rental car and calculates the price of the car. It is $50 per day and .08 cents per mile driven. Show this charge to the user and then add it to the hotel bill for the total bill for the stay. Show this total to the user as well with the person’s name booking the trip.

Mathematical functions introduced in chapter 4 can be used in the mathematical calculations and simulations of the engineering and scientific problems. In these cases, we formulate the mathematical problem and then use the computer for calculations and simulations. Can a computer code solve the math problem and come up with mathematical formulas, i.e. can a computer program do what a mathematician does?