Breakfast Discount

During my previous trip to Mexico City, I wrote about "El Péndulo", a chain of book stores / coffee shops that serve quite good food.  I went to one of them for breakfast last time, and when I paid my bill I received the little card pictured below.

On the card there is a literary question and three possible answers.  If you scratch the correct answer you get a discount on your next visit. 

The question was:  "Amor sin barreras" (Love Without Barriers) is based on what literary work?

I took a guess and scratched "Romeo and Juliet", and I was correct.  (I didn't know at the time that "Amor sin barreras" is the title given to "West Side Story" in Spanish America.)  I won a 15% discount.

Since the card was valid until September of this year, I put the card in my wallet and kept it.  Unfortunately, in my wallet one of the other answers was partially rubbed off, and I was unsure if my discount would be accepted.

On Wednesday I walked to "El Péndulo" again, and I had a very hearty breakfast.

I showed my card to the waiter, and he said that he couldn't give me a 15% discount, but he did give me a 5% discount. 

I received another card for my next visit, and the question on this card is...

Marilyn Monroe was married to what famous American writer?

I know that one without even having to guess!  The answer is Arthur Miller.

So, I shall return to "El Péndulo"... and I shall take good care of my card!