In C Language

Write two functions product1( ) and product2( ) that can multiply two integers and return the result. Function product1( ) takes only two parameters (n1) and (n2) which are both input parameters. The second function product2( ) takes an output parameter (p) in addition to those two input parameters. Write a program that opens a text file "integers.txt" to read two integers and calls the two functions product1( ) and product2( ) to test that they are working properly.