Problema Solution
A jar containes 6 blue marbles and 8 red marbles. Without looking,Jo reaches in and removes 4 marbles at once. What is the probability all 4 marbles are blue?
Answer provided by our tutors
the total number of marbles is 6 + 8 = 14
the number of favorable ways is C(6, 4) = 6!/(4!*2!) = 5*6/2 = 15
the total number of ways is C(14, 4) = 14!/(10!*4!) = 11*12*13*14/(2*3*4) = 1001
the probability that all 4 marbles will be blue marbles = 15/1001 = 0.01499