Question 1055832
This is a binomial probability problem.  The probability of success, i.e. getting a question right, is 0.2 (1 out of 5).
The formula is P(x) = C(n,x)*P^x*(1-P)^(n-x) where C(n,x) = n!/(x!(n-x)!), P is the probability of success
We must therefore compute P(8)+P(9)+p(10) since answering 8, 9 or 10 questions correctly results in a passing grade
Using a calculator or spreadsheet, we get P(8)=0.00007373, P(9)=0.000004096, and P(10)=0.0000001024.
The probability of passing is P(8)+P(9)+P(10)=0.00007793, a very unlikely outcome