20 persons are sitting in a particular arrangement around a circular table, 3 persons are to be selected for leaders. The number of ways of selection of 3 persons such that no 2 were sitting adjacent to each other is
Explanation
1. The General Formula
For a circular arrangement of n objects, the number of ways to select r objects such that no two are consecutive is given by:
Number of ways=n−rn×(rn−r)
In this specific problem:
2. Step-by-Step Calculation
Substitute the values into the formula:
Simplify the expression:
Now, calculate the combination (317):
3. Final Computation
Multiply the results: