schapman22
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Homework Statement
The time to failure for a certain light bulb in constant failure rate mode has a mean time to failure of 5000 hours.
What is the probability that a randomly chosen light bulb is still burning after 10,000 hours? Give answer to 4 decimals.
If 5 light bulbs are installed in different street lamps along Main Street, what is the probability that at least 1 will be working after 10,000 hours? Give answer to 4 decimals.
The Attempt at a Solution
I believe the first part would simply be e-(1/5000*10000)=.1353
The second part I am at a loss on how to solve it.