Serial Dilutions - 2
•Next calculate dilution in tube 2
•Dilution = 2 + 0.5    = 1:5 or 1/5
•                    0.5    
•so to calculate the serial dilution you multiply the dilution factor of each tube:
•    1   x   1  x   1  x   1   x   1   =     1        
•    3        5        5        5       5        1875