# Manufacturing machine probability problem

#### deathlives

##### New Member
There are three possible environment conditions: normal, rainy and hot. Rainy and hot days may be risky to a system that has been deployed, but normal days are safe.

It is expected that half of the days will have normal weather, one quarter will be rainy and one quarter will be very hot. Probability of failure on normal day is 0%, for rainy days 0.2% and for hot 0.1%. Assume the weather for the next day will be random, and that the effects of weather are statistically independent.

What is the probability of not having a failure for 120 days in a row?

#### Outlier

##### TS Contributor
Apparently, Mr. Afterlife wonders
What is the probability of not having a failure for 120 days in a row? under the constraints he/she gave.

#### ArtK

##### New Member
Apparently, Mr. Afterlife wonders
What is the probability of not having a failure for 120 days in a row? under the constraints he/she gave.
I think Rogojel was asking what Mr. Afterlife's question is ... not what the
stated problem is.

Art

#### deathlives

##### New Member
Mr. Afterlife is looking for a detailed answer to the question. A little confused with my answer and want to see what other living people come up with!