Olympiad simple..!

Or may be from MTG magazine :), coz i've picked it frm there and they hav given it to be frm Chinese Olympiad..

answer is indeed 119..from symmetry principle....[1][1]

It is 60,from the maximum likelihood principle,but that principle itself is not very reliable

mtg ni ho sakte ..........i hav done few of them .that to long back.i hav seen this sol also yaar.aab yaad ni aara sirf answer yaad hai :P

i dnt remebr d method xactly n alos d chap

bt u can say that d locomotive wich u c is d middle one so nw u hav total on avg 120 locomotives bt it includes d one wich u hav seen so -1 .

sumthng of dat sort ............

i guess itz frm tmh ...bt it can also b frm das gupta...ml khanna.........or ma clases notes :P

dats correct frm symmetry....

But one can also argue thsi way dat there r only 60 locomotives coz if there r 119, the probability of observing 60 is 1/119 and if der r 60, the probability is 1/60,so it's more probable..adn obviously der can't be 59!!!

119