Three fair dice are tossed. What is the probabiligy that the three numbers turned up can be arranged to form an arithmetic sequence?
I have an answer but I'm looking for someone who can explain how to do it
@Zarkon I am waiting for your explanation. Please, explain us.
list out some possible arithmetic sequences...in monotone order...there aren't that many. then permute them to get the total number
Do we have to raise to the power of 3 ? I meant let say 1-2-3 as one possibility, and 1 for dice 1, 2 for dice 2, and 3 for dice 3. The order can apply for 1 for dice 2, 2 for dice 1 and 3 for dice 3. So that we need to raise the possibility to 3, right?
1,2,3 1,3,2 2,1,3 2,3,1 3,1,2 3,2,1 3! possibilities for 1,2,3
Got you. Thanks for explanation.
132 is an arithmetic sequence?
No, I think one sequence can either increase or it can decrease. It can't do both.
" CAN be arranged to form an arithmetic sequence"
132 can be arranged as 123
123, 135, 234, 246, 345, 456 , so are you saying there would be 36?
there are more
not 3 factorial for each of those groups?
111,222,...,666 are arithmetic (common difference of 0)
Right so 42?
yes
The way to find the total number of different combos though?
you just did
No those were possible arithmetic sequences. I need a probability, so 42/x
6 possibilities for each die \(6^3=216\) total
then there's the fact that 116 is the same as 161 and 611
and...
out of the 216 possible ways to roll the dice we found 42 that can be arranged into an arithmetic sequence
Okay, thank you.
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