Supposed you go to a conference attended by 20 canadians and 20 norwegians. How many people must you meet to be certain that you have met two people of the same nationality?

3 people should be met to be certain that you have met two people of same nationality. So, the answer is 3 people.

Step-by-step explanation:

Total people in a conference = 20 canadians + 20 norwegians = 40 people.

The First person you meet out of 40 may be either 1 Canadian or 1 Norwegian.

If Canadian, then second person may be Norwegian or Canadian.

If Norwegian, then second person may be Canadian or Norwegian.

So, By the end of two persons: there may be the cases as

case 1: 1 Norwegian + 1 Canadian and vice versa

(or)

case 2: Two Canadians

(or)

case 3: Two Norwegians

Now, the case 1 does not satisfies the condition given in the question

So, the third person as the possibility of being either Norwegian or Canadian which satisfies the given condition in the question that you meet two people of same nationality.