Re: Probability question
- Posted by petelomax Jan 17, 2019
- 1457 views
I was privately emailed
(1001! / (143! ** 7)) / (7 ** 1001) 3.6330038905013278985302381744914316707641687749129 × 10^-9
which led me to compose
include bigatom.e bigatom p = ba_div(ba_div(ba_factorial(1001),ba_power(ba_factorial(143),7)),ba_power(7,1001)) ?ba_sprint(p) ?ba_sprint(ba_div(1,p))
output:
"0.0000000036330038905013278985302381" "275254315.7508172479064601750053166"
Which seems a bit too likely to me... (until I remembered I had asked a different question to the one lgregg answered...)
If I remember probability correctly ...
If you throw one die, the probability of one face coming up is 1/7. If you throw another die, and you want the same face to come up, the joint probability is (1/7) * (1/7), or (1/7)**2. Continuing for 1001 dice, the probability should be (1/7)**1001, or approximately zero. :)
Correct me if I am wrong!
I almost agree: If you throw one die, the probability of one face coming up is 100%(!). The second matches 1/7, rather than (1/7)*(1/7), leading to (1/7)**1000:
?ba_sprintf("%10.10eB",ba_power(1/7,1000)) ?ba_sprintf("%10.10eB",ba_power(7,1000))
giving:
" 7.9792116643e-846" " 1.2532566400e+845"
which almost feels far too unlikely... (until I think of 1e1000, then it feels about right)
Unfortunately, though, it isn't the question that I asked (143 of each, not 1001 all the same).
There are only five possible shapes made of the same regular shape for each face. So there is are no such die.
You're not wrong, but... https://www.thediceshoponline.com/dice/7511/Impact-Opaque-Black-White-D7-Dice or https://www.mathartfun.com/d357.html (two types), and while I'm not convinced myself, you could try making one of these: https://www.polyhedra.net/en/model.php?name-en=tetrahemihexahedron...
