1. ## special multiplication rule

Help! this is the problem:
a piece of complex technical equipment has 711 critical parts. If the probability of failure for each of these parts is 0.0001, find the probability of having at least one failure during a random use of the equipment. It tells me that I need to use the special multiplication rule, but without numbers plugged into the equation, I don't understand. Any help will be greatly appreciated.

2. Originally Posted by tonopahred
Help! this is the problem:
a piece of complex technical equipment has 711 critical parts. If the probability of failure for each of these parts is 0.0001, find the probability of having at least one failure during a random use of the equipment. It tells me that I need to use the special multiplication rule, but without numbers plugged into the equation, I don't understand. Any help will be greatly appreciated.
I haven't heard of the 'special multiplication rule', but I would find the probability using complement.

$Pr(At \ least \ one \ failure)=1-Pr(No \ Failures)$

$=1-(1-0.0001)^{711}$

$=0.069$