Taken from the Udemy course **Probability & Statistics for Business and Data Science**.

Consider the following question: “A company made a total of 50 trumpet valves. It is determined that one of the values (of 50) was defective. If three valves are used in a trumpet, what is the probability that a trump has a defective valve?”

Udemy: https://www.udemy.com/probability-and-statistics-for-business-and-data-science

## Solution

Probability of a valve from a batch of 50 being defective is:

P(E) = 1/50

This gives us 0.02 as the probability of getting that defective valve.

To calculate a trumpet having a defective valve (and trumpets have 3 values each), it would be:

P(E) = 3 x P(E defective valve) or 3 x 0.02, which is 0.06.