)[3 marks] List all the possible ways in which a counter starting on X can make exactly 3 visits to Y before the game ends. Beside each of these, record the probability of that journey, and add these up to get the overall probability V3 of making exactly 3 visits to Y before the game ends. 3/4 X Y 1/3 1/4 / 213 Z () [3 marks] Let Vn be the probability of making exactly n visits to Y before the game ends. In part (b) you found V3.Use this same kind of reasoning (listing all the possibilities) to find a formula for Vn for any n. Page 3 [3 marks] Calculate the sum of all the Vn's. X 3/4 Y 1/3 1/4 /213 Z