An exploding pen? Wow, I've never hada kilonetrico do that to me.
I take 2 black kilometrico, 2 blue kilometrico and 2 pencils into each exam (+ the other requried studd obviously). Test the pens the morning before the exam as well. I only used one pen for each of the English exam and neither run out (it was probably the same pen). If worst happened and all 4 pens ran out, then the pencils are a bakcup, a handy tip I picked up while camping in the American wilderness.
I take 2 black kilometrico, 2 blue kilometrico and 2 pencils into each exam (+ the other requried studd obviously). Test the pens the morning before the exam as well. I only used one pen for each of the English exam and neither run out (it was probably the same pen). If worst happened and all 4 pens ran out, then the pencils are a bakcup, a handy tip I picked up while camping in the American wilderness.