3. A bag contains 10 balls, 4 are red and 6 are yellow. Three balls are drawn without replacement. What is the probability of drawing at least two red balls?

4. A town has two fire engines operating independently. The probability that a specific fire engine is available when need is 0.95. What is the probability that neither is available when needed? What is the probability that a fire engine is available when needed?

OK could someone help out a little bit my brain is failing to work, I have done some working out but none of it seems to make sense and it seems easy. Don't know what's going on up there.