My Math Forum  

Go Back   My Math Forum > College Math Forum > Advanced Statistics

Advanced Statistics Advanced Probability and Statistics Math Forum


Reply
 
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 spring-loaded. When you push one of the buttons, the corresponding lock-pin on the top of the chest falls into place due to gravity. To let the lock return to the original position, you pull the lock-pin 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.
Attached Images
File Type: jpg lock.jpg (77.2 KB, 178 views)
davidbenjamindix is offline  
 
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.
mathman is offline  
Reply

  My Math Forum > College Math Forum > Advanced Statistics

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





Copyright © 2019 My Math Forum. All rights reserved.