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"we have discovered that by rolling 2 six sided dices and taking the sum all possibilities are not equally probable. 7s come far too often and 2s and 12s are rare
.....Your job is to relabel the 2 dice so that each of the sum from 2-12 is equally probable
what number should be on each dice?

2007-04-12 18:15:40 · 4 answers · asked by mysteriousjz 2 in Science & Mathematics Mathematics

4 answers

Interesting problem. I think that you should look at converting 4s and 3s to smaller and larger numbers. I'm really not sure that you can get all the sums from 2 to 12 to have equal probability.

Convert 3s to 1s and 4s to 6s and check.

Btw, do the two dice have to be the same once you're finished relabeling them?

2007-04-12 18:26:44 · answer #1 · answered by modulo_function 7 · 0 0

I don't see how this is possible. There are eleven numbers 2 thru 12. That means the probability for each number coming up would be 1/11. There are 6² = 36 possible rolls of the two dice. For probability to be 1/11 we need:

x/36 = 1/11
x = 36/11

But x is not an integer. There is no way each number can have 36/11 different ways to be rolled. I suppose you could have three ways to roll a number outside of 2 thru 12 leaving 33/11 = 3 ways for each of the numbers to be rolled, but I don't think that the question contemplates that kind of answer.

2007-04-13 01:32:11 · answer #2 · answered by Northstar 7 · 0 0

Easy

Put the numbers 20 - 25 on each die.

The probability of the sum being 2-12 is zero for each possibility.

Equally probable

QED

2007-04-13 02:09:25 · answer #3 · answered by z_o_r_r_o 6 · 1 0

I think its not possible. i justify my answer as follows
no of sums from 2 to 12 is 11
no of dice combo for two six-sided face is 36
36 is not divisible by 11
hence they cannot be equiprobable

2007-04-13 01:35:17 · answer #4 · answered by krishna 1 · 0 0

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