13Is there any shortcut formula??
6 dices are thrown together.Find the probability of getting a sum of 15.
What is the easiest and quickest way to do it?
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UP 0 DOWN 0 0 15
15 Answers
62a+b+c+d+e+f=15
u+v+w+x+y+z=9
15C6
first sove without any restriction on the upper limit.. takin lower limit as 0
then put the uppper limit as 5 (remove the cases when one of these is 6,7,8 or 9
this second part may seem difficult but is not actuallly
u just need to substitute u=k+5 (k>0) and multiply this number by 6.. (one for each u,v,w,x,y,z)
39Or....
a+b+c+d+e+f=15....positive integral solutions.....
WAT DO U MEAN SOUMIK???
THE SOLNS SHOULD BE BELONGING TO [1,6]
wat positive integral solns???????
19i doubt whether anyone spotted that in the process advised by soumik , you are actually getting a probability >1 ???????? how on earth is that possible ??
11Organic i just started probability pls can u explain your method and how it can be applied in any other problem ..pls
11Debotosh's method is the simple Generating-functions technique of combinatorics.....
19too big a name ....never knew that name but the process was known...thanks for the information !
19@virang....just get going with probability for some time......you will automatically be accustomed to the methods usable !!! ...anyways....this is an application for the chapter on permutations and combinations !!!
11And yes....b555, my method may be long, but obviously it can be done by that....do u want it?
39soumik i mean u did not pose the conditions on the solutions to the given equation. thats wat i mean.
i never said your method was wrong.
u did not give the conditions on a,b,c,d,e,f.....