I’m studying for my Computer Science class and don’t understand how to answer this. Can you help me study?

Problem 1.

Write a C program to print the contents of a text file line-by-line but backwards so that the last line is printed first. The filename should be specified as a command-line argument.

Problem 2.

Write a C program to convert a decimal number to binary in 32 bits. All 32 bits should be printed even if fewer bits are required to represent the number. The number should be specified as a command-line argument.

Problem 3. Write a C program to find out how many bits a variable of type long int is. Your program should not call any system functions (not even sizeof) and it should not include any .h files. (In other words, write your own code).