In detail

UN meeting

UN meeting

In the last meeting of the commission created to study the effects of climate change on earth, 5 people from different countries participated: Alberto, Benito, Carla, Daniela and Esteban. Since it was broadcast on television, a viewer could see that:

  • 1.- Benito and Carla always spoke in English, but when Daniela approached they spoke in Spanish since it was the only common language to all three.
  • 2.- Alberto, Benito and Esteban always spoke in French since it was the only language common to all three.
  • 3.- The only language Carla and Esteban had in common was Italian.
  • 4.- Three of the attendees knew German.
  • 5.- The most spoken language was Spanish.
  • 6.- Only one of the members of the commission knew the 5 languages, another knew 4, another knew three, another knew two languages ​​and one person only knew their own language.

What were the languages ​​spoken by each of the meeting attendees?

Solution

Alberto spoke Spanish, French and German. Benito spoke all languages. Carla spoke English, Spanish, French, Italian and German. Daniela spoke Spanish only. Finally, Esteban spoke Italian and French.

To solve this type of problem, the simplest procedure is to make a table with all the possible participants and languages ​​and gradually fill it in with the information provided by the statement.

From the first statement we can deduce that Benito and Carla know English so we put a S in the corresponding box. This same phrase also tells us that Daniela doesn't know English, so we put a letter N in the grid. However, the three (Benito, Carla and Daniela) know Spanish
so we can also put it on the table.

We complete the table analogously with the information provided by statements 2 and 3.

According to affirmation 3, we know that the only common language to Carla and Esteban is Italian and since Carla also knows English and Spanish, we put the letter N for Esteban in these two languages. In the same way we place N for Carla in the French language. The table is now shown as follows
way:

English Spanish French German Italian
Alberto S
Benedict S S S
Carla S S N S
Daniela N S
Esteban N N S S

Three people speak Spanish and French. Since we know that Castilian is the most spoken, we have to add one more person. From the information provided by the last sentence we know that there is a person who speaks a single language and looking at the table we see that it can only be Daniela so we complete all the boxes in her row with the letter N.

By affirmation number 4 we know that three people speak German. They cannot be Carla and Esteban simultaneously since their only common language was Italian so we can deduce that Alberto and Benito speak it. The last statement also tells us that there is a person who speaks 2 languages ​​exactly and we see from the table that only Esteban can be, so we complete the rest of the boxes in his row with the letter N.

The third one who knows German must then be Carla and we put the S correspondent.

By elimination, the person who knows exactly three languages ​​has to be Alberto so we fill in the boxes in his row with the letter N.

Finally, since we need a person who speaks the 5 languages, we check the box that is missing from Benito.