Complex sentence: If one selects a non-black thing at random, and it is a red apple, then the numerator will exceed the denominator by an extremely small amount; therefore seeing the red apple will only slightly increase one's belief that all ravens are black.
Split into simpler sentences: If one selects a non-black-thing at random, and it is a red apple, then the numerator will exceed the denominator by an extremely small amount. Therefore seeing the red apple will only slightly increase one's belief that all ravens are black.