What is the cost per pound for tool steel P20?

What is probability of getting 20 multiple choice questions wrong in a row?

Let us say that for each question, there are n multiple choices. If this is true and false, then n=2. The chance of getting a right answer is 1/n and wrong answer (n-1)/n. I will define p as getting a wrong answer one time (p = (n-1)/n so the probability of 20 wrong answers is p20. Now for n = 4, p=0.75 and the chance of 20 wrong answers in a row is: (0.75)20= 0.0032 or 0.32%.