... balls that contains at least one greenball. From this collection, pick a collection of n balls that contains at least one green ball.Then by the induction hypothesis, this collection of n balls ... “CAC”?(b) contain the word “CCC”? (c) contain the word “CDC”?(d) does not contain the word “CCD”?Lemma 2.1.4. Let M and N be two sets such that |M| = m and |N| = n. Then the totalnumber of distinct ... ℓ2, . . . , ℓ n 1, ℓ n+ 1. This collectionagain consists of n non-parallel lines and hence by induction hypothesis, all these lines passthrough a common point. This common point is P itself,...