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Title: A 13-year-old boy took less than a second to answer this maths problem Post by: TightEnd on May 16, 2017, 09:03:46 AM answers please
(https://pbs.twimg.com/media/C_5QoX6XoAAyIDV.jpg) Title: Re: A 13-year-old boy took less than a second to answer this maths problem Post by: RED-DOG on May 16, 2017, 09:11:08 AM answers please (https://pbs.twimg.com/media/C_5QoX6XoAAyIDV.jpg) I answered it in less than a second too. Title: Re: A 13-year-old boy took less than a second to answer this maths problem Post by: hector62 on May 16, 2017, 09:11:12 AM I am going for 25% of them.
Title: Re: A 13-year-old boy took less than a second to answer this maths problem Post by: Doobs on May 16, 2017, 09:34:39 AM I am going for 25% of them. I am with Hector. More than a second. Think it is pretty tricky to do in a second unless you have seen it previously. First thought is always 50%. Title: Re: A 13-year-old boy took less than a second to answer this maths problem Post by: TightEnd on May 16, 2017, 02:39:46 PM a chick can get pecked in there ways: from R, L, or both. each event has probability of (1/2)*(1/2)=1/4. total probability of being pecked is thus 3/4. so 1-3/4 =1/4 prob of not picked.
25 of 100 unpecked https://www.nytimes.com/2017/05/15/us/math-counts-national-competition.html?smid=tw-nytimes&smtyp=cur&_r=0 Title: Re: A 13-year-old boy took less than a second to answer this maths problem Post by: Doobs on May 16, 2017, 04:57:27 PM a chick can get pecked in there ways: from R, L, or both. each event has probability of (1/2)*(1/2)=1/4. total probability of being pecked is thus 3/4. so 1-3/4 =1/4 prob of not picked. 25 of 100 unpecked https://www.nytimes.com/2017/05/15/us/math-counts-national-competition.html?smid=tw-nytimes&smtyp=cur&_r=0 Love this comment. The contestants' achievements were the results of endless hours of practice and not necessarily innate math (sic) abilities. Have you read "thinking, fast and slow", Tighty. I have just started reading it, but I think it is going to be very good. Very much like "Fooled by Randomness". Anyway this looks a classic example. Your instinct tells you it is 50%, but you really need to step back and think the problem through. Unless it was in your practice questions anyway! |