Problema Solution
A bag contains 5 purple marbles and 7 yellow marbles. One marble is drawn and not replaced. Then a second marble is drawn. What is the probability that the first marble is yellow and the second one is purple?
Answer provided by our tutors
12 marbles total for the first draw, 7 of which are yellow:
7/12
11 marbles total for the second draw, 5 of which are purple:
5/11
these are sequential, random events so we multiply their probabilities together:
(7/12)(5/11) = 0.265
there is a 26.5% probability of randomly drawing a yellow marble followed by randomly drawing a purple marble