# airplane engines?

assume that airplane engines operate independently of each other and that at least half of the engines on a plane must operate for the plane to continue flying. A particular airplane engine fails with a probability of 1/7. which is safer an airplane with 2 of these engines or an airplane with 4 of these engines?

### 1 Answer

- CharlesLv 41 decade agoBest Answer
I won't answer the question, but I will try to walk you through the process of answer the question. Based on the question an airplane is safe as long as half the engines are functioning.

For the 2 engine plane, it is safe as long as 1 or 2 engines are working. If no engines are operating, it is unsafe (duh!).

For the 4 engine plane, it is safe as long as 2, 3, or 4 engines are working. If 1 or no engines are operating, it is unsafe.

These are both binomial distributions with p = 6/7 and n = 2 or 4. You can calculate the probability of being safe or unsafe using the binomial distribution.