Or you can just shuffle them from the start:
my $num = shift;
my @init = (0..$num-1);
my @questions;
while (<>) {
  $questions[splice @init, rand(@init), 1] = $_, next if $. <= $num;
  my $i = rand($.);
  $questions[$i] = $_ if $i < $num;
}

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In reply to Re: Re (tilly) 2 (unrandomness): Extract random records from text file by runrig
in thread Extract random records from text file by SuperCruncher

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