a) find the probability that there are three men with beard and two with no beard.

Find the probability of exactly three men having a bread (that implies other two doth not).

To do that use binomial probability,

5C3 (1/10)^3(9/10)^2

What is probability of selecting two men?b)if two people are selected randomly from the people in the room, what is the probabiliy that both of them are men with beard?

5C2/8C2

That means the probability of selecting two men.

What is probability of both having beards?

(1/10)(1/10)=1/100

Now multiply the two numbers you get for final answer.