Out of 6 boys and 4 girls, a group of 7 is to be formed. In how many ways can this be done if the group is to have a majority of boys?
100
Form different cases in which boys are in majority compare to girls.
Case1: 1 girl and 6 boys, No. of ways they can be selected =4C1×6C6=4
Case2: 2 girls and 5 boys, No. of ways they can be selected = 4C2×6C5=36
Case3: 3 girls and 4 boys, No. of ways they can be selected = 4C3×6C4=60
Hence total ways 60−36+4=100 .