a certain law firm consist of 4 senior partner and 6 junior partner. how many different group of 3 partners can be formed in which at least one member of the group is senior partner..........
The required number of ways = Total possible groups of 3 - No. of groups of 3 without a senior partner. = A - B
A = 10C3 = 120
B = 6C3 = 20
Therefore the required no of groups of 3 with at least 1 senior partner = 120-20 = 100.
