There are 15 boys and 10 girls in a class. If three students are selected at random, in how many ways that 1 girl or 2 boys are selected ? Answers
A) 100 B) 105 C) 115 D) 120 E) 125
n(s) = sample space = 251153 = 2300   E = event that 1 girl and 2 boys are selected   n(E) = we have to select 2 boys from 15 or 1 girl from 10   = 151152 + 101151   = 115   Ans - 115
<result>C</result>
There are 15 boys and 10 girls in a class. If three students are selected at random, in how many ways that 1 girl or 2 boys are selected ?