answer these in c++?!

Question 5 Please select all the valid statements (a valid statement is the statement that doesn't cause a compiler error): v float var; var - 1; char var '11 int var 1: int var - 1: Int var: string var - 113 double var - 1: Question 9 To open and output file and add to the end of the data already in the file what function and parameters would you write? outfile.open("myFile.txt", ios app): outfile.append("myFile.txt"); outFile.open("myFile.txt", append); outFile.open("myFile txt")