Question

Four students (K, L, M, N) participate in four competitions (Quiz, Debate, Chess, Coding), one event each.
1. K does not do Quiz or Chess.
2. L does Coding.
3. N does not do Debate.
4. M does not do the same event type as K.
How many valid assignments are possible?

Hint:

When each person must take a unique role, assign the most constrained individuals first. This reduces the search space dramatically.

Answer 1

Correct Answer: 2

This puzzle collapses quickly once you notice two of the five clues do no real work. L is fixed to Coding, and since K is barred from Quiz and Chess, Coding being taken means K must be Debate, there is no other option left. That single deduction also satisfies the "N does not do Debate" rule automatically, because Debate is already gone to K by the time N is considered, and the "M is not the same event as K" rule is true in every valid assignment anyway, since no two students ever share an event. So the only real freedom left is handing Quiz and Chess to M and N, which can be done in 2 ways. The answer is 2.