Hello,

Yep, binomial.

Resume : 4 questions -> n=4. 4 possible answers -> p=1/4

Thus this is a binomial distrubition X ~ B (4,1/4)

That is to say the mean of the variable. E(X)=np=1 (Binomial distribution - Wikipedia, the free encyclopedia)1. How many questions would you expect to get right?

P(X=4)=^4C_4 * p^4 * (1-p)^{4-4}=p^4=1/4^4=1/642. What’s the probability that you get all four questions correct?

P(X >= 2)=1-P(X < 2)=1-P(X=0)-P(X=1)3. What’s the probability that you get at least 2 questions correct?

Try this one