When a Road Crew Inspects a Road That Hasn't Been $\mathrm { e } ^ { \mathrm {b} }$

When a road crew inspects a road that hasn't been worked on for several years, then the distance between necessary repairs is an exponential random variable with a mean of 0.25 miles. What is the probability that the crew will find a mile long stretch of road that does not need repairs? Enter your answer as just $\mathrm { e } ^ { \mathrm {b} }$ .