The teacher has 15 posters, of which 3 are colored and 12 are black & white.
a) If the teacher decides to only use 10 posters, determine how many arrangements can be made? Determine an answer to this problem 2 different ways. /2
b) If the teacher uses all 15 posters, but wants to have a black & white poster at each end, determine the number of arrangements that can be made? /1
c) If the teacher uses all 15 posters, but wants all the colored posters to be side-by-side, determine the number of arrangements that can be made? /1