(Q). In a class of 12 students 7 are boy & rest are girls. In how many ways students can be selected for the project such that at least 1 boy & 1 girl is selected.
Solution:-
Nuber of ways of selecting one or more boys is (2⁷ – 1) = 127 ways
Number of ways of selecting one or more girl is (2⁵ – 1) = 31 ways
Hence required number of ways is 127×31 = 3937 Answer
