Browse · MATH
Printjmc
counting and probability intermediate
Problem
The planning committee at school has 11 members. Exactly five of these members are teachers. A four-person subcommittee with at least one member who is not a teacher must be formed from the members of the planning committee. How many distinct subcommittees are possible?
Solution
Because there are 5 teachers on the committee, there are 6 non-teachers. Now, in total, we can form subcomittees. The number of subcommittees with zero non-teachers is the number of subcommittees formed by the 5 teachers, totaling . So, the number of subcomittees with at least one non-teacher is .
Final answer
325