In a group of 14 students, how many different ways can you select a team of 3 students to participate in a quiz if at least 2 of them must be from a specific grade?
19
18
10
13
To solve this problem, we'll consider two cases: when exactly 2 students are chosen from the specific grade and when all 3 students are chosen from the specific grade.
Case 1: Exactly 2 students from the specific grade are chosen.
In this case, we need to select the remaining 1 student frorn the remaining 14-2=12 students (excluding the 2 from the specific grade).
Number of ways to select 1 student from 12=12 C1
Case 2: All 3 students from the specific grade are chosen.
There is only 1 way to select all 3 students from the specific grade.
To calculate the total number of ways to form the team, we need to sum up the possiblities from both cases:
Total number of ways = Number of ways in Case 1+ Number of ways in Case 2
Total number of ways =12 C1+1
Now, let's calculate the value:
Total number of ways =12+1=13
Therefore, there are 13 different ways to select a team of 3 students to participate in the quiz, where at least 2 of them must be from a specific grade.
Study 40% syllabus and score up to 100% marks in JEE