A seller of online educational software would like to evaluate the effectiveness of a recent marketing campaign. The seller has contacted 70% of schools in a city to provide marketing material about a new software programme. Of the schools that were contacted, 30% adopted the new software. Of the schools that were not contacted, 10% adopted the new software. A school is randomly chosen from this city, and two events are defined as follows: = The school was contacted = The school adopts the software A. Are and mutually exclusive? Are they collectively exhaustive? Briefly explain. (3points) B. What is the probability that a school who adopts the software was contacted? (4 points) C. What is ( )? (3 points)