<H2>Suppose that the lifetime of a light bulb is exponentially distributed and that the expected lifetime is 250 hours.

Suppose that we switch on the light bulb at midnight and then we check at midnight every day afterwards in order to see if the light bulb is still burning.

Let Xn=1 if the bulb is still burning and Xn=0 if it has burnt out, where n=1,2,3,… is the number of days after we start the light bulb.

Sketch two sample paths of for n=1 to 10

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