While watching tv I saw a quiz, suppose you have a 100 euro banknote, how often can you change that note into other notes ( including another 100e note )? In Europe we have 100, 50, 20, 10 and 5 euro notes. For example changing my 100e note to 2x50e or to 1x50e+5x10e or 2x20e + 1x10 + 10x5. Here is my try to solve the puzzle, but it is more a try and error than a solve.

my $cnt;
for my $f ( 0 .. 20 ) {
  for my $z ( 0 .. 10 ) {
    for my $zw ( 0 .. 5 ) {
      for my $fu ( 0 .. 2 ) {
        for my $hu ( 0 .. 1 ) {
          $cnt++ if $f * 5 + $z * 10 + $zw * 20 + $fu * 50 + $hu * 100
+ == 100;
        }
      }
    }
  }
}
print $cnt;
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How would you do it?

2004-11-11 Edited by Arunbear: Changed title from 'How to solve this puzzle in a better way?', as per Monastery guidelines