Need Help answering these questions In C (not C++)

Correct the errors in the following C code segments, or write "correct" if the code is free of errors. You may assume that any variables referenced in the code have already been declared. 1. FILE fetr fopen("test.txt r open file for reading 2. if(fptr NULL0 printf cannot open file! n'');exit 3. while (f (fptr3, "o/od" &data) EOF) printf(i Cube of 9%d is %dIn", data, data data data 4. FILE in, out, appendi declare three file pointers 5. out fopen( "output, txt "a"); open file for append