Answer:
Step-by-step explanation:
For each component, there are only two possible outcomes. Either it fails, or it does not. The components are independent. We want to know how many outcomes until r failures. The expected value is given by

In which r is the number of failures we want and p is the probability of a failure.
In this problem, we have that:
r = 1 because we want the first failed unit.
![p = 0.4[\tex]So[tex]E = \frac{r}{p} = \frac{1}{0.4} = 2.5](https://tex.z-dn.net/?f=p%20%3D%200.4%5B%5Ctex%5D%3C%2Fp%3E%3Cp%3ESo%3C%2Fp%3E%3Cp%3E%5Btex%5DE%20%3D%20%5Cfrac%7Br%7D%7Bp%7D%20%3D%20%5Cfrac%7B1%7D%7B0.4%7D%20%3D%202.5)
The expected number of systems inspected until the first failed unit is 2.5
Answer:

Step-by-step explanation:
The result is given by means of some algebraic handling:

- Multiplication of rationals.
- Dividing each term by 2.
- Dividing each term by 2.
- Dividing each term by 3.
When dividing same numbers with different exponents (they’re both 10 so this works different than if they were different numbers) you subtract the top exponent by the bottom exponent. So 15-4=11 ultimately making the solution 10^11. Hope this helps :)