8. We have looked at situations in which we need to determine the number of possible routes between two places. We can look at the situation below as 9 steps, six of which must be East and three of which must be South. . This gives us 3?('),, possible routes. The calculation 3?('31 is equivalent to 9C3 (or 2C* ). Explain why you could solve this question using combinations and why this solution is equivalent to considering permutations with repeated items. (4 marks)