Question 1199214
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Two solutions using standard probability methods....<br>
(1) You are choosing 2 of the 19+28 = 47 marbles; the number of ways to do that is "47 choose 2":
{{{C(47,2)=(47+46)/(2*1)=1081}}}<br>
The "good" outcomes are when you choose 2 of the 19 red marbles; 19 choose 2:
{{{C(19,2)=(19*18)/(2*1)=171}}}<br>
The probability is (# good outcomes)/(# of possible outcomes):
ANSWER: 171/1081<br>
(2) Find the probability of getting a red on the first draw and then getting another red on the second draw:
{{{(19/47)*(18/46)=171/1081}}}<br>
Same answer, of course....<br>