bonanova Posted March 30, 2008 Report Share Posted March 30, 2008 A number is said to be rotated when its leftmost digit is moved to the right end, and the other digits shift to the left. 3117 becomes 1173, 1731, 7311 and finally 3117 again, on successive rotations. It turns out that the Centigrade representations of certain temperatures are the rotation of the Farenheit representations. For example, if 413 degrees F were 134 degrees C - but it's not. What is the lowest temperature for which this is true? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2008 Report Share Posted March 30, 2008 1 - Assuming numbers below "absolute zero" are not relevant, and 2 - Assuming the temperatures are expressed as integers. Lowest rotated Fahrenheit temperature to Celsius: -425F = -254C (if the negative symbol is an issue, 40F = 04C; there is also 61F = 16C; 82F = 28C...) Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted March 31, 2008 Author Report Share Posted March 31, 2008 1 - Assuming numbers below "absolute zero" are not relevant, and 2 - Assuming the temperatures are expressed as integers. Lowest rotated Fahrenheit temperature to Celsius: -425F = -254C (if the negative symbol is an issue, 40F = 04C; there is also 61F = 16C; 82F = 28C...) Great job Kid, , but looking for rotated integers for C. Hint: every 9th F gets you integer C.. -425 -> -253.88... 40 -> 04.44... [clever with the 0...] 61 -> 16.11... 82 -> 27.77...[/code] Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2008 Report Share Posted March 31, 2008 Hello This is my try Well I dont think there is any such number. At least not till 100000F Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2008 Report Share Posted March 31, 2008 Well using excel, I did the following Column A, start with 32 and each following cell +9 Column B, =(Cell A - 32) * 5/9) Column C ==ALUE(RIGHT(Cell A,(LEN(Cell A)-1))&LEFT(Cell A)) This returns 32 as 23, or 41 as 14 Column D =IF(Cell C = Cell A, True, False) Added a autofilter, and discovered that between 589,838 and -589,838 there is only one solution that is valid. (For the negatives, I compared absolute numbers) 527F = 275C If not comparing absolute numbers, I think there is one more solution; -40F = -40C, Moving the left most part of -40F and rotating returns 40F- which 40 = 40 All the way around.. However, this is a far fetched idea. Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted March 31, 2008 Author Report Share Posted March 31, 2008 PolishNorbi has done it again, winning the coveted rotated trophy award. Good job. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2008 Report Share Posted March 31, 2008 What other number(s) fit the answer by going through the full rotation? There is one other answer. Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted April 1, 2008 Author Report Share Posted April 1, 2008 The F/C temperature pairs that are integers make C multiples of 5. Restricting F values not to have a leftmost digit of 0, we have C=5+10N and F=41+18N. Since C ends in 5, F must begin with 5. For each power of 10, there is one possibility for a rotated match. These are the ones I've found - either an exact match, or the closest to it.59 -> 15 527 -> 275 <- match 5297 -> 2925 52943 -> 29395 529403 -> 294095 5294111 -> 2941155 <- near miss 52941173 -> 29411745 <- near miss 529411757 -> 294117625 5294117651 -> 2941176455[/code] Quote Link to comment Share on other sites More sharing options...
0 Guest Posted April 1, 2008 Report Share Posted April 1, 2008 The F/C temperature pairs that are integers make C multiples of 5. Restricting F values not to have a leftmost digit of 0, we have C=5+10N and F=41+18N. Since C ends in 5, F must begin with 5. For each power of 10, there is one possibility for a rotated match. These are the ones I've found - either an exact match, or the closest to it.59 -> 15 527 -> 275 <- match 5297 -> 2925 52943 -> 29395 529403 -> 294095 5294111 -> 2941155 <- near miss 52941173 -> 29411745 <- near miss 529411757 -> 294117625 5294117651 -> 2941176455 What about 35195F = 19535C or 35195 -> 51953 -> 19535 (We have a match on second rotation) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted April 2, 2008 Report Share Posted April 2, 2008 im sorry but that is kinda creapy Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted April 3, 2008 Author Report Share Posted April 3, 2008 What about 35195F = 19535C or 35195 -> 51953 -> 19535 (We have a match on second rotation) Excellent! Quote Link to comment Share on other sites More sharing options...
0 Guest Posted April 3, 2008 Report Share Posted April 3, 2008 (edited) Found two more: 44024F = 24440C 24440 => 44402 => 44024 (We Have a match)(This is doing in reverse order) 219551F = 121955C 121955 => 219551 (We have a match) (This is doing in reverse order) Reverse order ie; 527 = 275 => 752 => 527 not like before where it was one rotation Then my computer program crashed at 219551 so I will have to wait to continue up to 1,000,000,000,000,000 Edited April 3, 2008 by PolishNorbi Quote Link to comment Share on other sites More sharing options...
0 Guest Posted April 3, 2008 Report Share Posted April 3, 2008 Found two more: 44024F = 24440C 24440 => 44402 => 44024 (We Have a match)(This is doing in reverse order) 219551F = 121955C 121955 => 219551 (We have a match) (This is doing in reverse order) Reverse order ie; 527 = 275 => 752 => 527 not like before where it was one rotation Then my computer program crashed at 219551 so I will have to wait to continue up to 1,000,000,000,000,000 3666020 = 2036660 => 0366602 => 3666020 (Bingo!) 8547485 = 4748585 => 7485854 => 4858547 =>8585474 => 5854748 => 8547485 (Bingo!) Computer Froze at 10,000,000 Again Quote Link to comment Share on other sites More sharing options...
Question
bonanova
A number is said to be rotated when its leftmost digit is
moved to the right end, and the other digits shift to the left.
3117 becomes 1173, 1731, 7311 and finally 3117 again,
on successive rotations.
It turns out that the Centigrade representations of certain
temperatures are the rotation of the Farenheit representations.
For example, if 413 degrees F were 134 degrees C - but it's not.
What is the lowest temperature for which this is true?
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