C Programming

It’s a very easy assignment hence the price. Hardly 1 hour. I just don’t have the time.
I need all the functions, a .h file, a makefile and a read me.
It has to be plagiarism-free.
Please do not use any high-end programming code because this is a first-year undergraduate assignment.
The function mentioned in the instructions is as follows:
double rand_double(double a, double b)
{
double rtrn;
int c=0;
rtrn = ((double)rand()/(double)RAND_MAX) * (b-a)+a;
c++;
return rtrn;
}