Answer: 8/9
Step-by-step explanation:
First, we can find a common denomiator.
The least common multiple of 2, 9, and 6 is 18.
Therefore, the lcd is 18.
1/2 = 1/2 * (9/9) = 9/18
2/9 = 2/9 * (2/2) = 4/18
1/6 = 1/6 * (3/3) = 3/18
Therefore, 1/2 + 2/9 + 1/6 = 9/18 + 4/18 + 3/18.
We can add the numerators together.
= 16/18
Divide the nuumerator and denominator by 2:
= 8/9
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:
52
Step-by-step explanation: