wolfgang Posted March 30, 2011 Report Share Posted March 30, 2011 (edited) Give me five different even numbers with a total sum of 20. The numbers should be all(+). You shuold not repeat any number twice. The numbers should be added together (only) to give us a total of 20. Zero(0) is not included. Edited March 30, 2011 by wolfgang Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 Reveal hidden contents 2,4,4,4 and 6? I didn't repeat a number twice I repeated it thrice. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 Reveal hidden contents 4+4+4+4+4=20 Meets all criteria... Quote Link to comment Share on other sites More sharing options...
0 fabpig Posted March 30, 2011 Report Share Posted March 30, 2011 On 3/30/2011 at 6:30 PM, rlgandy said: Reveal hidden contents 2,4,4,4 and 6? I didn't repeat a number twice I repeated it thrice. Reveal hidden contents If you're going to split hairs, you DID repeat it twice. 4,4 is repeating it once! . But it also says 5 different numbers. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 (edited) Reveal hidden contents 2, 4, 6, 8, and 10 in base 20? Edited March 30, 2011 by thirdtimescharm Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 Reveal hidden contents 2, 4, 6, 8 and 10 in base 15? The ten being in the one's place. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 (edited) Well, this is a conundrum ... Reveal hidden contents While fractions are never considered even or odd, if the definition of an even number is (loosely speaking) evenly divisible by 2, then wouldn't a fraction like 8/10ths be even? Here's my answer: 8/10, 12/10, 2, 6, 10. Edited March 30, 2011 by JAPrufrock Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 (edited) On 3/30/2011 at 7:21 PM, rlgandy said: Reveal hidden contents 2, 4, 6, 8 and 10 in base 15? The ten being in the one's place. Reveal hidden contents But, in a Base 15, wouldn't these numbers (all non-fractioned numbers) be (technically) odd? Edited March 30, 2011 by JAPrufrock Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 30, 2011 Report Share Posted March 30, 2011 On 3/30/2011 at 7:27 PM, JAPrufrock said: Well, this is a conundrum ... Reveal hidden contents While fractions are never considered even or odd, if the definition of an even number is (loosely speaking) evenly divisible by 2, then wouldn't a fraction like 8/10ths be even? Here's my answer: 8/10, 12/10, 2, 6, 10. The definition of an even number is any number that can be written as 2n where n is an integer. Quote Link to comment Share on other sites More sharing options...
0 curr3nt Posted March 30, 2011 Report Share Posted March 30, 2011 Reveal hidden contents Base 15 would be the first base that would work. 2+4+6+8+A=20 in base 15 Since those number occur before 10(base 15) they are still even. 10(base 15) is where the "even" numbers are odd until 20(base 15) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2011 Report Share Posted March 31, 2011 On 3/30/2011 at 8:00 PM, curr3nt said: Reveal hidden contents Base 15 would be the first base that would work. 2+4+6+8+A=20 in base 15 Since those number occur before 10(base 15) they are still even. 10(base 15) is where the "even" numbers are odd until 20(base 15) Reveal hidden contents You're right ... I'm confused. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2011 Report Share Posted March 31, 2011 Using different bases Reveal hidden contents 2 + 4 + 8 + 10 (base 2) + 100 (base 2) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted March 31, 2011 Report Share Posted March 31, 2011 Reveal hidden contents 20 written in base N will be translated in : 20= 2*N^1 + 0* N^0 = 2*N. Now , considering that all the number we are adding are even, we can take out 2 of the sum like this: A1= 2*a A2=2*b A3=2*c A4=2*d A5=2*e. So the sum would look like this: A1+A2+A3+A4+A5 = 20. applying the above calculation, we get: 2( a+b+c+d+e) = 2 * N. this is equivalent to a+b+c+d+e = N. in here, N is the base, a,b,c,d,e are greater then 0 integers. The smallest greater then 0 (distinct) integers are 1,2,3,4,5 which add up to 15. So the smallest base this works in is 15, with a unique solution to the question. From here on, you can increase the base by 1 and find number that respect the relation above. for base 16 you will 1 set of numbers that respects it: (1,2,3,4,6) and the even number would then be (2,4,6,8,12). for base 17 you have 2 sets of numbers that respect it: (1,2,3,4,7) (1,2,3,5,6) with the even number just multiply this by 2 and so on. So the answer for this question exists in any base greater or equal then 15. Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 1, 2011 Author Report Share Posted April 1, 2011 On 3/30/2011 at 6:50 PM, thirdtimescharm said: Reveal hidden contents 2, 4, 6, 8, and 10 in base 20? but you did an additional processe(base),you should(add) only. Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 1, 2011 Author Report Share Posted April 1, 2011 On 3/30/2011 at 7:27 PM, JAPrufrock said: Well, this is a conundrum ... Reveal hidden contents While fractions are never considered even or odd, if the definition of an even number is (loosely speaking) evenly divisible by 2, then wouldn't a fraction like 8/10ths be even? Here's my answer: 8/10, 12/10, 2, 6, 10. Here,you are going to devide and add,while I said ,you should (add) only. Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 1, 2011 Author Report Share Posted April 1, 2011 On 3/31/2011 at 2:02 PM, Fesoj said: Reveal hidden contents 20 written in base N will be translated in : 20= 2*N^1 + 0* N^0 = 2*N. Now , considering that all the number we are adding are even, we can take out 2 of the sum like this: A1= 2*a A2=2*b A3=2*c A4=2*d A5=2*e. So the sum would look like this: A1+A2+A3+A4+A5 = 20. applying the above calculation, we get: 2( a+b+c+d+e) = 2 * N. this is equivalent to a+b+c+d+e = N. in here, N is the base, a,b,c,d,e are greater then 0 integers. The smallest greater then 0 (distinct) integers are 1,2,3,4,5 which add up to 15. So the smallest base this works in is 15, with a unique solution to the question. From here on, you can increase the base by 1 and find number that respect the relation above. for base 16 you will 1 set of numbers that respects it: (1,2,3,4,6) and the even number would then be (2,4,6,8,12). for base 17 you have 2 sets of numbers that respect it: (1,2,3,4,7) (1,2,3,5,6) with the even number just multiply this by 2 and so on. So the answer for this question exists in any base greater or equal then 15. well..there is Quote Link to comment Share on other sites More sharing options...
0 plainglazed Posted April 1, 2011 Report Share Posted April 1, 2011 Reveal hidden contents 2 + 4 + 6 + 8 = 20 --> five unique, non-negative, non-zero, even integers whose sum is 20? Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 2, 2011 Author Report Share Posted April 2, 2011 On 4/1/2011 at 1:22 PM, plainglazed said: Reveal hidden contents 2 + 4 + 6 + 8 = 20 --> five unique, non-negative, non-zero, even integers whose sum is 20? well...I see only four integers..2,4,6 and 8 Don`t take it as a pure mathmatics....its a trick... Quote Link to comment Share on other sites More sharing options...
0 Guest Posted April 2, 2011 Report Share Posted April 2, 2011 On 3/30/2011 at 6:04 PM, wolfgang said: Give me five different even numbers with a total sum of 20. The numbers should be all(+). You shuold not repeat any number twice. The numbers should be added together (only) to give us a total of 20. Zero(0) is not included. Does (+) = positive? If not, use negatives, like... Reveal hidden contents 2, 4, 8, 10, -4 Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 3, 2011 Author Report Share Posted April 3, 2011 On 4/2/2011 at 9:52 PM, typodestoyer said: Does (+) = positive? If not, use negatives, like... Reveal hidden contents 2, 4, 8, 10, -4 +...is...+ but not(positive)...and not(negative) Quote Link to comment Share on other sites More sharing options...
0 wolfgang Posted April 5, 2011 Author Report Share Posted April 5, 2011 Reveal hidden contents +5 EVEN Quote Link to comment Share on other sites More sharing options...
Question
wolfgang
Give me five different even numbers with a total sum of 20.
The numbers should be all(+).
You shuold not repeat any number twice.
The numbers should be added together (only) to give us a total of 20.
Zero(0) is not included.
Edited by wolfgangLink to comment
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