In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:

Let S be the sample space and E be the event of selecting 1 girl and 2 boys.

Then, n(S) = Number ways of selecting 3 students out of 25

                =  $25C3$  = 2300.

         n(E)= $10C1*15C2$ = 1050. 

P(E) = n(E)/n(s) = 1050/2300 = 21/46