Question

Successful implementation of a new system is based on three independent modules. Module 1 works properly with probability 0.9, Module 2 works properly with probability 0.84, and Module 3 works properly with probability 0.65. What is the probability that at least one of these three modules will fail to work properly?

Answer 1

The probability is 0.5086

Explanation:

The probability P that at least one of these three modules will fail to work properly is calculated as:

P = 1 - P'

Where P' is the probability that all the modules works properly. So, P' os calculated as:

P' = 0.9 * 0.84 * 0.65

P' = 0.4914

Because 0.9 is the probability that module 1 works properly, 0.84 is the probability that module 2 works properly and 0.65 is the probability that module 3 works properly.

Finally, the probability P that at least one of these three modules will fail to work properly is:

P = 1 - 0.4914

P = 0.5086