(June 4, 2011 at 8:53 am)Stue Denim Wrote: It works like this, It's 10! (3.6 mill) If I have 10 things, an A,B,C,D,E,F,G,H,I and a J and then arrange them in an order. There are 10! (3.6 million) different combinations, However, this assumes that I can't use the same x twice, once it's down, its down and cannot be used again (10! is the same as 10x9x8x7x6x5x4x3x2x1, When i start I have a choice of 10 things, however once I've put the first one down and am ready to put the 2nd one down, there are only 9 to chose from, when I go to put the 3rd one down there are only 8...). Randomly picking 10 digits however allows for me to use the same digit twice, or three times... it doesn't matter if its already been used, allowing for 10x10x10x10x10x10x10x10x10x10 (10^10). Each time there are 10 choices, as the number of choices doesn't diminish at each step. The person randomly chose a 10 digit sequence, its 10^10.Thanks for clearing that up. I knew factorials were used in calculating probability somehow but I couldn't get any other answer than 10^10.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell
