<PRE><B>Question 1033923</B>
We use the binomial probability formula for this problem
:
Probability(P) = 1/4 for guessing a question correctly
:
P(guessing 3 problems correctly) = 10C3 * (1/4)^3 * (3/4)^7
:
Note 10C3 = 10! / (3! * 7!) = 10*9*8 / (3 * 2) = 120
:
********************************************************************
P(guessing 3 problems correctly) = 120 * (1/64) * (2187/16384) = .1%
********************************************************************
:</PRE>