You're right about the mistake, except that what grep returns is already a hashref so by adding [ ] around it, you make an array of array

You can just provide a list context to the expression with ($usefulans,) (the comma is optional, but I put it there to show that the parenthesis is there to force list context), which will put the first result into $usefulans and drop the others. But since there should be only one match ...

$VAR1 = [
          [
            'a',
            'W',
            'interupt'
          ],
          [
            'b',
            'R',
            'interrupt'
          ],
          [
            'c',                                                      
+                                                                     
+                                                                     
+                    
            'W',                                                      
+                                                                     
+                                                                     
+                    
            'innterupt'                                               
+                                                                     
+                                                                     
+                    
          ],                                                          
+                                                                     
+                                                                     
+                    
          [                                                           
+                                                                     
+                                                                     
+                    
            'd',                                                      
+                                                                     
+                                                                     
+                    
            'W',                                                      
+                                                                     
+                                                                     
+                    
            'intterupt'                                               
+                                                                     
+                                                                     
+                    
          ]                                                           
+                                                                     
+                                                                     
+                    
        ];                                                            
+                                                                     
+                                                                     
+                    
($answer,) = grep { $$_[0] eq 'b' } @$VAR1;                           
+                                                                     
+                                                                     
+                    
print "@$answer";
[download]

b R interrupt

But oakb, you should consider a hash (with answer id as the key). You could easily turn your array into one with : %hash = map { shift @$_ => $_ } @$qablock Then you'd just have to do $hash{$givenAnswer} to get ['w', 'interupt']