Question 907171:  Can you please help me with this word problem I do not know where to start. 
 
A bag of Hershey Kisses may contain anywhere from 51 to 57 kisses. How many bags would you need to buy to ensure that you have at least 3 bags with the exact same number of kisses?  
 Answer by josmiceli(19441)      (Show Source): 
You can  put this solution on YOUR website! I would call this a problem about 
Worst Case Scenarios ( WCS ) 
------------------------------ 
If you are drawing bags from a randomly 
mixed barrel of bags, and you draw 
7 bags, what is the WCS if you are  
looking for 3 bags with the same number 
------------------------------------ 
The WCS is that you draw 51, 52, 53, ... 57 
to start with, or, no duplicates at all 
----------------------- 
But if you draw 1 more bag, you are now 
guaranteed 1 duplicate 
----------------------- 
Each time you pick 7 more bags, you are 
guaranteed in a WCS, that you will only  
get another duplicate, but not the one 
you wanted 
----------------- 
If you do   picks, then you 
are guaranteed 2 of each kind as a WCS 
----------------- 
On the 50th pick of bags, you are finally 
GUARANTEED a WCS of 3 bags with the 
same number of kisses 
----------------- 
An example of a WCS series of 7 picks is: 
(1) 51, 52, 53, 54, ... 57 
(2) 51, 51, 51, 51, ... 51 
(3) 52, 52, 52, 52, ... 52 
(4) 53, 53, 53, 53, ... 53 
.  
. 
. 
(7) 57, 57, 57, 57, ... 57 
------------------------ 
Note that you don't have 3 that 
are the same yet, but 1 more 
pick guarantees that you will 
------------ 
So, you need to pick 50 bags
 
 
 
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