Решение задачи N4249 теория вероятностей

4249. The device consists of two nodes, which during operation can independently fail from each other. Let the probability of failure-free operation of the first unit during the warranty period equal to 0.75, and the second - 0.8. Find the likelihood that during the warranty period the device: a) will work properly; b) will fail (i.e. at least one of the components of the device will fail).

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)