Q. There are 26 students in a homeroom. How many different ways can they be chosen to be elected President, Vice President, and Treasurer?Answer:
Understand the Problem: Understand the problem.We need to find the number of different ways to choose 3 students from a group of 26 for the positions of President, Vice President, and Treasurer. This is a permutation problem because the order in which we choose the students matters (choosing student A for President and student B for Vice President is different from choosing student B for President and student A for Vice President).
Set up Formula: Set up the permutation formula.The number of ways to arrange n items into r specific places is given by the permutation formula:P(n,r)=(n−r)!n!Where n is the total number of items to choose from, r is the number of items to choose, and “!” denotes factorial.
Apply Formula: Apply the permutation formula to our problem.In this case, n=26 (the total number of students) and r=3 (the number of positions to fill).P(26,3)=(26−3)!26!
Calculate Permutation: Calculate the permutation.P(26,3)=23!26!To avoid calculating the large factorials, we can expand the factorials and cancel out the common terms.P(26,3)=23!26×25×24×23!The 23! in the numerator and denominator cancel each other out.P(26,3)=26×25×24
Perform Multiplication: Perform the multiplication.P26,3 = 26×25×24= 15600So, there are 15,600 different ways to choose a President, Vice President, and Treasurer from 26 students.