Need help with this one, I'm stuck

3. The probability is 0.3 that a traffic fatality involves and intoxicated or alcohol-impaired driver. Assume that the probability distribution for X , the number of traffic fatality involve an intoxicated impaired driver in eight traffic fatalities is a binomial distribution with n = 8 probability of success p = 0.30. Notice that in this case we have: 8 P( X = x) = (0.30) * (0.70) 8 -x, x = 0,1, ...,8. x a. In eight traffic fatalities, find the probability that the number which involve an intoxicated impaired driver is exactly 4. A b. In eight traffic fatalities, find the probability that the number which involve an intoxicated impaired driver is at most 4