A marksman finds that on average he hits the target 9 times out of every 10 and scores a bull's eye on the average once every 5 rounds. He fires 4 rounds. What is the probability that:
He scores at least 2 bull's eyes and he has hit the target on each of the four rounds?
I have found that the prob he scores at least 2 bulls eyes to be 0.1808
and the prob of hittign the target all four times to be 0.6561
what i am not sure how to do is combine them