Need Help to solve math puzzle

[burgess]

Three students are selected randomly in a class of 15 boys and 10 girls, Then what is the the probability that 2 boys and 1 girls are selected?

Thanks in advance

[shyamjayakannan]

There are all the cases: 3 boys, 2 boys and 1 girl, 1 boy and 2 girls, 3 girls. Let's add the total possibilities for all these cases:
total = [tex]^{15}C_3+{}^{15}C_2{}^{10}C_1+{}^{15}C_1{}^{10}C_2+{}^{10}C_3=2300[/tex]

So, probability of selecting 2 boys and 1 girl = [tex]\frac{^{15}C_2{}^{10}C_1}{2300}=\boxed{0.456}[/tex]