Working with serial dilutions.

You performed the following dilution series on a culture of Escherichia coli:

1 ml of the original culture to 99 ml broth
then 1 ml cell suspension to 9 ml broth
then 2 ml to 8 ml broth
then 0.1 ml to a culture plate

The next day, you count 52 colonies on the plate. What was the concentration of the original culture? (Hint: Drawing the dilution series may help.)