tag:blogger.com,1999:blog-4115025577315673827.post4773755858371448884..comments2019-12-04T14:40:09.489+05:30Comments on CSE Blog - quant, math, computer science puzzles: Coins PuzzlePratik Poddarhttp://www.blogger.com/profile/11577606981573330954noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-4115025577315673827.post-13321310542134085942013-09-11T14:36:37.805+05:302013-09-11T14:36:37.805+05:30Excellent, thanks for this. It was winding me up ...Excellent, thanks for this. It was winding me up not knowing the answer.<br /><br />NB: "Not flip the coins" should read "Now flip the coins".Brian Carterhttps://www.blogger.com/profile/05832031303676274452noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-4386847277271035822010-01-02T00:07:29.717+05:302010-01-02T00:07:29.717+05:30Sorry for my mistake. Reposted the second part and...Sorry for my mistake. Reposted the second part and now the correct solution for both parts. Thanx Vivek.<br /><br />First part:<br />Divide 100 coins in two sets of 50 coins each.<br /><br />The first set has x heads up coins and 50-x tails up coins.<br />The second set has 50-x heads up coins and x tails up coins.<br /><br />Not flip the coins in the second set. So, both have x coins heads up and 50-x coins tails up. :)<br /><br />Second part:<br />Divide 100 coins in two sets, one of 10 coins and other of 90 coins.<br /><br />The first set has x heads up coins and 10-x tails up coins.<br />The second set has 90-x heads up coins and x tails up coins.<br /><br />Not flip the coins in the first set. So, both have x coins tails up.<br /><br />Hence, done. :)<br />Thanx again vivek (@viki).Pratik Poddarhttps://www.blogger.com/profile/11577606981573330954noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-50129740784604749232009-11-03T23:36:46.461+05:302009-11-03T23:36:46.461+05:30"This obviously implies that the two have equ..."This obviously implies that the two have equal number of coins with heads face up".<br /><br />That was just for 50 heads and 50 tails in the beginning.vikihttps://www.blogger.com/profile/00394691204629747462noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-71099887438058424792009-11-03T20:25:14.913+05:302009-11-03T20:25:14.913+05:30Second part of the question was wrong. Hence remov...Second part of the question was wrong. Hence removed.<br /><br />@viki<br />The question said that we have to divide the 100 coins into two sets of 50 coins each such that both have equal number of heads up. Your method divided it into two unequal parts.Pratik Poddarhttps://www.blogger.com/profile/11577606981573330954noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-84971120289234412162009-11-03T19:29:18.755+05:302009-11-03T19:29:18.755+05:30Divide into two regions of 10 coins and 90 coins.....Divide into two regions of 10 coins and 90 coins...then flip a;; coins of the heap of 10 coins.<br />If originally there were x heads among those 10 then there were (10-x) heads among 90. Flipping the 10 coin set will give you x tails and (10-x) heads in that set.<br />So,you get (10-x) heads in both.vikihttps://www.blogger.com/profile/00394691204629747462noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-54006042416599756052009-11-03T09:43:28.860+05:302009-11-03T09:43:28.860+05:30hit me with the solution!! :Dhit me with the solution!! :DPratik Poddarhttps://www.blogger.com/profile/11577606981573330954noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-33198513813462260732009-11-03T09:40:28.836+05:302009-11-03T09:40:28.836+05:302nd part...you gave incorrect solution....Solution...2nd part...you gave incorrect solution....Solution is "deterministic" and simple.....few operationsvikihttps://www.blogger.com/profile/00394691204629747462noreply@blogger.comtag:blogger.com,1999:blog-4115025577315673827.post-65783569636030942952009-10-31T13:38:36.330+05:302009-10-31T13:38:36.330+05:30For the first part, divide 100 coins in two sets o...For the first part, divide 100 coins in two sets of 50 coins each.<br /><br />The first set has x heads up coins and 50-x tails up coins.<br />The first set has 50-x heads up coins and x tails up coins.<br /><br />Not flip the coins in the second set. So, both have x coins heads up and 50-x coins tails up. :D<br /><br />For the second part,<br />Doing the same operation again and again, we will approach towards the solution.Pratik Poddarhttps://www.blogger.com/profile/11577606981573330954noreply@blogger.com