A girl has exactly 6 quarters, 6 dimes, and 10 nickels in her pocket. If she withdraws a number of these coins at random, how many coins would she have to withdraw to ensure that she has at least a 50 percent chance of withdrawing at least one quarter?	Pick one:	A) 1	B) 2	C) 3	D) 4	E) 5
When the probability of NOT drawing a quarter is 50% or less, then the probability of drawing a quarter is at least 50%.   P(not drawing a quarter with 2 coins) = 16/22 * 15/21 = 40/77 &gt; 50%   P(not drawing a quarter with 3 coins) = 40/77 * 14/20 = 4/11 &lt; 50%   The answer is 3.
<result>C</result>
A girl has exactly 6 quarters, 6 dimes, and 10 nickels in her pocket. If she withdraws a number of these coins at random, how many coins would she have to withdraw to ensure that she has at least a 50 percent chance of withdrawing at least one quarter?