
Advanced Statistics Advanced Probability and Statistics Math Forum 
 LinkBack  Thread Tools  Display Modes 
January 7th, 2013, 02:40 PM  #1 
Newbie Joined: Dec 2012 Posts: 10 Thanks: 0  Possibilities with thirteen numbers
This is similar to one of my previous posts, but is quite different. There are 13 buttons (numbered 1, 2, 3, .....13)in this combination lock, and you have to figure out which ones can be pressed in. They can either be pushed in or left into their original extended position. You don't know how many buttons need to be pushed in (or left pushed out) to solve the lock (it could be none, 1, 3, 8, or all 13). How many possibile combinations are there? Any how do you arrive at that answer? Here's a photo of my lock. The buttons are in the front of the blanket chest and are springloaded. When you push one of the buttons, the corresponding lockpin on the top of the chest falls into place due to gravity. To let the lock return to the original position, you pull the lockpin upwards and the spring forces the button back out. After each attempt at pushing the buttons, the longer bar on top of the chest gets pushed down. If the combination is correct, you can push the bar all the way down. If incorrect, it only depressed part of the way. 
January 7th, 2013, 03:31 PM  #2 
Global Moderator Joined: May 2007 Posts: 6,805 Thanks: 716  Re: Possibilities with thirteen numbers
Final answer 2^13. Expand (1+1)^13 binomial. The kth term is the number of ways that k buttons can be pushed.


Tags 
numbers, possibilities, thirteen 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Triangle possibilities  ewler  Algebra  2  May 14th, 2013 08:02 AM 
Math Possibilities  martapag  Elementary Math  4  January 23rd, 2013 08:02 AM 
Coin Purchase Possibilities  testtrail429  Algebra  1  October 11th, 2012 12:57 AM 
The possibilities of the dice of numbers 1 3 (?)  Keroro  Algebra  4  June 5th, 2012 06:05 PM 
Possibilities  tuloon  Algebra  1  April 9th, 2009 11:56 AM 