binomial expansion

Despite the great hopes and the money spent to take Cristina to Santiago, that first Spanish experience ended in disappointment for herself, family and friends.

One of those techniques that had been invented in Compostela with EU approval to get troubled students pass their Mathematics exams consisted of two steps. In the first, the student was invited to choose the subject matter on which he or she would like to be questioned. In the second, he or she was handed a single sheet examination with one question about that subject matter written on the front page and the answer to that very same question written on the back.

Cristina decided to choose binomials. She felt great about binomials. She claimed she had done in her life more than fifteen thousand exercises on binomials. She had no single doubt she knew everything there was to be known in the whole World about binomials. She confidently informed the teacher:

"My preferred subject is binomials".

The teacher consulted his computer files, series 3476 (Binomials), subseries 3476-235 (Binomial Expansion) and asked Cristina:

"Could it be a question on binomial expansion, señora Cristina?"

"Oh, for sure, sir, any question you want about that", she answered.

He then run a random selection program in his computer and question 3476-235-1817 was chosen. He made a print of it. The exam sheet in his hand, he told Cristina very professionally.

"Señora Cristina, here you have your question about binomial expansion. Please remember that the answer is written on the back".

"Oh, I do not need any help on this subject, professor. I will do it on my own.", she said with a confident smile on her face.

She felt so at ease that she even took the teacher's own pen to write on the front page of the exam a little note to her friend Pedro who was back home eating his nails for news about her.

She then jumped on the question. A few minutes later she handed in the exam paper to the teacher and left the classroom, mobile in her right hand, to phone Pedro about the good news. This time it was for sure, she would pass the Math exam.

Half an hour later, the uniformed teacher entered the hallroom where she and other students were waiting.

"Cristina Keller", he announced: "Failed".

This was her only experience in a Spanish speaking country. As the plane landed in Buenos Aires, she wondered how she would survive in Argentina with such a meagre experience in castellano.