tag:blogger.com,1999:blog-1974366466896776665.post3422461804663263326..comments2022-03-27T05:59:34.842-05:00Comments on Math Problem of the Day: Triple 6Davidhttp://www.blogger.com/profile/09232747857608296294noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-1974366466896776665.post-28004242403446127782009-09-22T10:57:53.297-05:002009-09-22T10:57:53.297-05:00The answer is 150.
If three dice are thrown, the ...The answer is 150.<br /><br />If three dice are thrown, the probability of NOT getting triple sixes is 1-(1/6)^3 = 215/216. So the probability of not getting triple sixes in n throws is (215/216)^n<br /><br />Now we solve an inequality.<br />(215/216)^n < 0.5<br />log[(215/216)^n] < log(0.5)<br />n * log(215/216) < log(0.5)<br />n > log(0.5)/log(215/216) = 149.37...<br />n >= 150Davidhttps://www.blogger.com/profile/09232747857608296294noreply@blogger.com