Question 1046976
You have 90 balls altogether. 20 of them are white, 25 are blue, 
27 are red, and 18 are green. Now you will draw a ball one at a 
time randomly until you've drawn any of the following: either 11 
white, 9 blue, 3 red, or 14 green. What is the minimum number of 
balls you have to draw until you are 100% sure that you've gotten 
one of the previous combinations? 
<pre><b>
The most number of balls you could possibly have drawn and failed 
is to have drawn 10 whites, 8 blues, 2 reds and 13 greens. That
case is possible when 10+8+2+13=33 balls are drawn.  You would 
necessarily have more than 10 whites or 8 blues or 2 reds or 13 
greens in any other case of drawing 33 balls.  That is to say, 
any other case when 33 balls have been drawn will be a success.  
But even in that extreme case, if you draw one more ball, you 
must succeed.

Answer: 34 balls.  

Edwin</pre></b>