The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, Southwest Air had the best rate with 80% of its flights arriving on time. A test is conducted by randomly selecting 12 Southwest flights and observing whether they arrive on time.
(a) Find the probability that at least 10 flights arrive late.
(b) Would it be unusual for Southwest to have 3 flights arrive late? (Enter YES or NO)