Need help on survey of residents, forming a committee

I cannot seem to figure these two problems out.

1: A survey of residents in a certain town indicates 170 own a dehumidifier, 130 own a snow blower, and 80 own a dehumidifier and a snow blower. How many own a dehumidifier or a snow blower?

2: A committee of 6 people is chosen from a group of 6 men and 5 woman. What is the probability that the committee will consist of 4 men and 2 women?

I am kind of new to the probability stuff so any help would be appreciated.

Re: Need help on problems

For your first question, don't you just add them all together, since it's one OR the other?