Five years of an exponential lifetime

Topic: Random variables and distributions · more questions on this topic
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A component has an exponential lifetime with rate \lambda=1/10 per year. Find the probability that it is still working after 5 years.

Worked answer (click to show)

\mathbb{P}(X>5)=e^{-(1/10)\cdot 5}=e^{-1/2}\approx 0.607.