Subscribe via feed.Trick of MindThere is No SpoonHomeRegisterKid Sister RuleYour PuzzleAuthorsFAQragknotPosted by ragknot under Tom (1 Respond)I forgot what this site is for? I have brain errors and forget lots of think. But I saw this web link and I come her to remember what I was for. I see I had a log in, so learn what it is for?  “Trick of Mind” sounds familiar, but I forgot what I came her for?Find the missing numberPosted by Chris under Tom (3 Responds)A Mr. Piyush has posted the following:Find the missing number5 : 24 :: 8 : xOptions are:a. 65b. 63c. 62d. 64Communicating recipientsPosted by Zorglub under Tom (5 Responds)Three recipents R(0), R(1) and R(2) each contain an integer volume v0(0) ≥ v0(1) ≥ v0(2) ≥ 1.  Each recipient is large enough to contain the combined volumes.  You are allowed to transfer some liquid from one recipient to another, only if the receiving one doubles its volume.  Show that there is always a way to empty out one recipient in finitely many steps.Example: If the initial volumes are 17,  8,  5 the sequence of volumes could beR(0)  R(1)  R(2)17      8      517     3       1017     6       717     12      116     12     214     12     414      8      814      16     0  =>  R(2) is finally empty.Easy as 123451Posted by Zorglub under Tom (5 Responds)A function f takes a positive integer and returns another one by moving the leftmost digit to the right.For example f(12345) = 23451What is the smallest strictly positive integer n such that f(n) = 1.5 nA yes/no testPosted by Chris under Logic,  MathsChallenge (6 Responds)In a test involving yes/no answers, the probability that the official answer is correct is t, the probability of getting the real correct answer is b for a boy and g for a girl. If the probability that a randomly chosen boy or girl of getting the official answer to a question is 1/2, then what is the ratio of boys to girls who took the test?It’s as easy as a, b, cPosted by Chris under MathsChallenge (6 Responds)Find all solutions in positive integers a, b, c to the equationa! b! = a! + b! + c!916238457Posted by Chris under MathsChallenge (13 Responds)916238457 is a nine-digit number that has the property that has the digits 1 to 9 exactly once and the digits 1 to 5 are in counting order but the digits 1 to 6 are not. How many such numbers are there?Golden Needle in a HaystackPosted by DP under MathsChallenge (7 Responds)I have a very large plot of land on which I have stacked bales of hay, each measuring 1m x 1m x 1m. They are stacked 10 bales high, and span a couple thousand wide and deep. To keep them out of the weather I have also placed a tarp on top that cannot be seen through and should not be walked on or cut open in any way.While stacking the hay I also stored several boxes of gold for safe keeping, but did not mark down where. However, to make it a little easier for my future self I grouped 8 boxes together so that they occupy a 2m x 2m x 2m space.I now need some of my gold,