Probability of incorrect classification in majority vote

Question

In a supervised learning problem, I have 11 models, which have an error rate of 0.2 What is the probability of an incorrect prediction?

equation

I have the equation (n/k)p^k(1-p)^n-k but something is just not clicking.

Would this be (11/6).8^6(.2)^5 ?

Answer 1

Probability of an incorrect prediction is the same as not getting every model predicted correctly. Hence the value is $$1-\binom{11}{11}(0.2)^{0}(0.8)^{11-0}=1-0.8^{11}\approx0.9141$$