Answer:
Decimal reduction time 
 cells per minute
 cells per minute
Step-by-step explanation:
Given -
Initial population of cells 

Final population of cells 

Total change in population of cells is equal to final population of cells minus the initial population of cells.
Total change in population of cells 

Total time taken by cell to reduce 
 minutes
 minutes
Decimal reduction time 
 cells per minute
 cells per minute