What is the minimum number of students needed in a class to guarantee that there are at least 6 students whose birthdays fall in the same month?

Key Points

Pigeon hole principle: 

In general, if K is a positive integer and KN+1 pigeons are distributed among 'n; pigeon holes then some hole contains at least K+1 pigeons.

This problem is the same as the above concept, the minimum number of students needed in a class to guarantee that there are at least 6 students whose birthdays fall in the same month over a year. A year has 12 months So,

\(12 \times 6 +1= 61\)

The minimum number of students are=61.

Hence the correct answer is 61.