Serial dilution Q:

From a stock, 1.0 mL of bacteria is transferred to 9 mL of water until you reach a 10^-6 solution. Assume that on your final plate you counted 150 colonies from the 10^-6 solution where you plated 0.1 mL. Work backwards to show the CFU/mL you would expect to find in each step of the serial dilution and include the volumes transferred between each tube. What would the mutation frequency be if you counted 25 colonies from a 10^-2 dilution where you plated 0.1 mL of this culture?