Question 275790
on a 10 question multiple choice test, each question has 1 correct response and three that are incorrect. If at random, a student circles an answer for each question:
a) What is the probability that she will get the first three and last two right? 
1/4 x 1/4 x 1/4 x 3/4 x 3/4 x 3/4 x 3/4 x 3/4 x 1/4 x 1/4
= {{{2.317428589x10^-04}}}

 b) What is the probabilty that she will get any 5 right?

P(x=5) = 10C5*(1/4)^5*(3/4)^5
= binompdf(10,1/4,5) = 0.0584..
Cheers,
Stan H.