Solve the problem.
-The number of different committees of 2 students where the 2 students are selected from a group of n students is given by $c ( n ) = \frac { 1 } { 2 } \left( n ^ { 2 } - n \right)$ n). How many different committees of 2 students can be selected from a group of 10
Students?
A)10
B)20
C)45
D)1

Question

Quizplus · Accepted Answer

The formula for the number of different committees of 2 students from a group of n students is $c(n) = \frac{1}{2}(n^2 - n)$. Substituting $n = 10$, we get $c(10) = \frac{1}{2}(10^2 - 10) = \frac{1}{2}(100 - 10) = \frac{1}{2}(90) = 45$.

Solve the Problem c(n)=12(n2−n)c ( n ) = \frac { 1 } { 2 } \left( n ^ { 2 } - n \right)c(n)=21​(n2−n)

Solve the Problem $c ( n ) = \frac { 1 } { 2 } \left( n ^ { 2 } - n \right)$