Answer:
Answer is 24288.
Step-by-step explanation:
Given that there are 18 senior and 22 junior partners.
To find:
Number of ways of selecting at least one junior partner to form a committee of 3 partners.
Solution:
At least junior 1 member means 3 case:
1. Exactly 1 junior member
2. Exactly 2 junior member
3. Exactly 3 junior member
Let us find number of ways for each case and then add them.
Case 1:
Exactly 1 junior member:
Number of ways to select 1 junior member out of 22: 22
Number of ways to select 2 senior members out of 18: 18 [tex]\times[/tex] 17
Total number of ways to select exactly 1 junior member in 3 member committee: 22 [tex]\times[/tex] 18 [tex]\times[/tex] 17 = 6732
Case 2:
Exactly 2 junior member:
Number of ways to select 2 junior members out of 22: 22 [tex]\times[/tex] 21
Number of ways to select 1 senior member out of 18: 18
Total number of ways to select exactly 2 junior members in 3 member committee: 22 [tex]\times[/tex] 21 [tex]\times[/tex] 18 = 8316
Case 3:
Exactly 3 junior member:
Number of ways to select 3 junior members out of 22: 22 [tex]\times[/tex] 21 [tex]\times[/tex] 20 = 9240
So, Total number of ways = 24288
