Finding Binomial probability

[neckbone40]

In a certain college, 20% of the physiscs majors belong to ethnic minorities. If 10 students are selected at random from the physics majors, what is the probability that exactly 2 belongs to an ethnic minority?

Please explain the approach... I'm swimming in stats.

Neckbone40

 

[pka]

\(\displaystyle P(X=2)=\binom{10}{2}(.2)^2(1-0.2)^{10-2}=\frac{10\cdot 9}{2\cdot 1}(.2)^2(0.8)^{8}\)