Sterilization is a batch process by which bacteria and molds in food are killed by heat treatment. A can of vegetables that originally contained 10,000 viable spores has 100 spores remaining after heating for 10 min at 250 F. Assuming first-order kinetics, how long must this can be heated at this temperature to reduce the probability of having a single spore to an average of 1 in 1 million cans?