Your code works fine, but it includes 250 and excludes 500.

Direct quote from perldoc -f rand:

               Apply "int()" to the value returned by "rand()" if you 
+want
               random integers instead of random fractional numbers.  
+For
               example,
 
                   int(rand(10))
 
               returns a random integer between 0 and 9, inclusive.
[download]

my @answers=();
push @answers,(int(rand(251))+250) foreach (0..99);
[download]

What I meant was that from reading the OP's code, it generates random numbers between 0 and 100, but does it 250 times. The algorithm is backwards.