The decimal reduction time (D-value) is the time required to reduce the number of viable spores by 90%. Given that the total process time is 3 minutes and each can has 20 spores, we can calculate the number of viable spores remaining using the formula:
\[
\text{Probability of spoilage} = 1 - 10^{-\frac{\text{Process time}}{\text{Decimal reduction time}}}
\]
Substituting the values:
\[
\text{Probability of spoilage} = 1 - 10^{-\frac{3}{1.6}} = 1 - 10^{-1.875} = 1 - 0.013 \approx 0.987.
\]
Thus, the probability of spoilage in each can is approximately 0.987. For 100 cans, the expected number of spoiled cans is:
\[
0.987 \times 100 \approx 99.
\]
Thus, the probability of spoilage in 100 cans is approximately 28.