The principal would like to assemble a committee of 7 students from the 12 -member student council. How many different committees can be chosen?Answer:
Q. The principal would like to assemble a committee of 7 students from the 12 -member student council. How many different committees can be chosen?Answer:
Identify Problem Type: Identify the type of problem.We need to find the number of ways to choose 7 students out of 12 without regard to the order in which they are chosen. This is a combination problem, not a permutation, because the order does not matter.
Use Combination Formula: Use the combination formula.The number of combinations of n items taken k at a time is given by the formula:C(n,k)=k!(n−k)!n!where n! denotes the factorial of n, which is the product of all positive integers up to n.
Apply Formula: Apply the formula to our problem.Here, n=12 (the total number of students) and k=7 (the number of students to choose for the committee).C(12,7)=7!(12−7)!12!
Simplify Expression: Simplify the expression.C(12,7)=7!×5!12!C(12,7)=(5×4×3×2×1)(12×11×10×9×8)
Perform Calculation: Perform the calculation.C(12,7)=5×4×3×2×112×11×10×9×8C(12,7)=112×111×210×39×48C(12,7)=12×11×5×3×2C(12,7)=12×11×5×3×2C(12,7)=12×11×30C(12,7)=3960