I am not sure what the objective is. However, a couple of possibilities come to mind... map{} can return a conditional thing...use () to return "nothing". See below. 
#!/usr/bin/perl -w
use strict;

my $VAR1 = [
          [
            'a',
            'W',
            'interupt'
          ],
          [
            'b',
            'R',
            'interrupt'
          ],
          [
            'c',
            'W',
            'innterupt'
          ],
          [
            'd',
            'W',
            'intterupt'
          ]
        ];
        
print "Number of Questions: ", scalar @$VAR1, "\n";

#@$VAR1 produces a list of references to the arrays
#The map selects the 2nd one of each array, index [1]
#the grep in a scalar context counts them up

print "Number right: ", scalar( grep{/r/i}map{@$_[1]}@$VAR1 ), "\n";
print "Number wrong: ", scalar( grep{/w/i}map{@$_[1]}@$VAR1 ), "\n";

#Maybe the question is which one is the "right" answer, a,b,c,d?
print "\n";
print "correct answer is: ", map{@$_[1] =~ /r/i ? @$_[0]:()}@$VAR1;

__END__
Number of Questions: 4
Number right: 1
Number wrong: 3

correct answer is: b
Process completed successfully

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In reply to Re^5: grep and dereferencing an array of arrays by Marshall
in thread grep and dereferencing an array of arrays by oakb

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