[math] \newcommand{\NA}{{\rm NA}} \newcommand{\mat}[1]{{\bf#1}} \newcommand{\exref}[1]{\ref{##1}} \newcommand{\secstoprocess}{\all} \newcommand{\NA}{{\rm NA}} \newcommand{\mathds}{\mathbb}[/math]

A company buys 100 lightbulbs, each of which has an exponential

lifetime of 1000 hours. What is the expected time for the first of these bulbs to burn out? (See Exercise Exercise.)