Question

A class contains 10 boys and 6 girls.If a committee of 3 is chosen at random from this class the probabity that exactly 2 boys are selected is?​

Answer 1

Total number of possible committee = 16C3

i) number of possible committee having 3 boys = 10C3

probability = 10C3 /16C3

ii) number of possible committee having exactly 2 boys = 10C2* 6C1

probability = 10C2*6C1 /16C3

 

iii) number of possible committee having at least one boy = 16C3 - 6C3

probability = [ 16C3 - 6C3 ]/16C3

iv) number of possible committee having exactly 2 girls = 6C2* 10C1

probability = 6C2*10C1 /16C3