The document announces that Test 2 will take place on March 22nd, 2011 at 8pm in the big Hall, and Test 4 will take place on April 5th, 2011 at 8pm in the big Hall. It then discusses serial dilution, noting that plates with too much or not enough growth are hard to count colonies from, but plates with definite single colonies allow for the best estimate of CFU. It asks the reader if they got an answer of 5.6 x 108 CFU/ml for a calculation involving serial dilution.