daiske1 Report post Posted October 17, 2008 (edited) One was a person gave to me and i couldn't do it. Ok...10 digit number- find it. 1 digit- far left- is divisible by 1. The first 2 digits form a number divisible by 2. The first 3 digits form a number divisible by 3. you get the pattern. and all 10 digits form a number divisible by 10. I just thought about it but do you just have to add. Or can you subtract, multiply, or divide because it says "forms". I say it is impossible if you add because no matter how much you rearrange it. You will get 45 as your sum of all 10 numbers so its impossible to get to the all 10 digits. (it has to be a whole number) so try to figure it out. Took me an hour then i thought about adding all 10 digits and figured this out. Really was a waste of time. I just figured out from the person that you don't have to add or subtract. For example: the first 2 digits could be 12. Then those 2 digits are divisible by 2. So my clumsiness on my part. Edited October 17, 2008 by daiske1 Share this post Link to post Share on other sites
Raz Report post Posted October 17, 2008 Nice one Daiske..... Took me about 30 minutes to work it out - and it can be worked out... without *huge* amounts of trial and error! (I won't post the answer here in case anyone else wants to try) I will forum pm you the answer. Share this post Link to post Share on other sites
2coolfool Report post Posted October 17, 2008 There are loads of solutions, in the hundreds I bet. Found 18 so far. Share this post Link to post Share on other sites
daiske1 Report post Posted October 17, 2008 nice 2cool. Yep i am noobish like that to give hard probs. Here i another one. 2coolfool and Raz are best friends. Raz is a Lilliputian, 12 inches tall. 2coolfool is a Brobdingnagian, 60 feet tall. (nice) raz is taking human growth hormones and his height is increasing at the rate of 4 inches a year. 2coolfool is tired of bumping his head everywhere he goes; therefore, he is taking shrinking pills, and his height is reducing by 44 inches a year. They started taking their medicines on January 1, 1990. How many years will it take before they become the same height? Include the year, month, and day. How tall will they be when they are the same size? Just found another one. Don't want to try it out. Share this post Link to post Share on other sites
Mar(c) Report post Posted October 18, 2008 (edited) There are loads of solutions, in the hundreds I bet. Found 18 so far. Yeah, even over 2000 I think... The lowest match is 1020005640. Unless I missed a clue... The 10 digits don't need to be all different ones, or do they? In that case: 3816547290 (not sure if there are more [edit]ok, pretty sure that's the only one [/edit]). edit: How many years will it take before they become the same height? Include the year, month, and day. How tall will they be when they are the same size? 12 + 4x = 60*12 - 44x 48x = 708 x = 14.75 12 + 4*14.75 = 60*12 - 44*14.75 = 71 So after 14.75 years (on October 1, 2004), they were both 71 inches tall. Edited October 18, 2008 by Mar(c) Share this post Link to post Share on other sites
daiske1 Report post Posted October 20, 2008 nice...algebra.............A+ Share this post Link to post Share on other sites
Raz Report post Posted October 20, 2008 And another.. The date 29-9-1992 (29th September 1992) is the last date that is a palindrome... When is the next one using the above format...... At some point in the future - 2 such dates less than a week apart... when? (and we will be all long dead by then) Share this post Link to post Share on other sites
Slavia Report post Posted October 22, 2008 You're in a concrete cube, with no doors and no windows. All you have is a table and mirror. How do you get out? Share this post Link to post Share on other sites