1. Two pollsters will canvas a neighborhood with 20 houses. Each pollster will visit 10 of the houses. How many different assignments of pollsters to houses are possible? 2. An box contains 4 blue and 7 red balls. Players A and B withdraw balls from the box consecutively until a red ball is selected. Find the probability that A selects the red ball. (A draws the first ball, then B, and so on. There is no replacement of the balls drawn.)