Question

An experiment involves 30 participants. From these, a group of 4 participants is to be testedunder a special condition. How many groups of 4 participants are possible?

Answer 1

We want to choose a group of 4 participants from a total of 30 participants. In this case, any body can be in the group. This means that order does not matter. If order does not matter, we are dealing with combination. To choose r from n whn dealing with combination, it is

nCr

Thus, we would find

30C4 = 27405

the number of possible groups is 27405