Find $5$ numbers where the sum of all pairs gives the results $110, 112, 113, 114, 115, 116, 117, 118, 120,...












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Find $5$ numbers where the sum of the pairs gives the results $110, 112, 113, 114, 115, 116, 117, 118, 120, 121$




I have been trying on this question for some time and it seems easy at first glance, but later on, I was unable to start on the question. I tried turning these into equations with $a_1, a_2, a_3, a_4, text{ and }a_5$ but couldn't as it is not determined which $2$ numbers give which sum. I was, however, able to achieve that $a_1+a_2+a_3+a_4+a_5=289$ (which is obvious). Now is there anyway I could continue without guessing. Thank you.










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    4












    $begingroup$



    Find $5$ numbers where the sum of the pairs gives the results $110, 112, 113, 114, 115, 116, 117, 118, 120, 121$




    I have been trying on this question for some time and it seems easy at first glance, but later on, I was unable to start on the question. I tried turning these into equations with $a_1, a_2, a_3, a_4, text{ and }a_5$ but couldn't as it is not determined which $2$ numbers give which sum. I was, however, able to achieve that $a_1+a_2+a_3+a_4+a_5=289$ (which is obvious). Now is there anyway I could continue without guessing. Thank you.










    share|cite|improve this question









    $endgroup$















      4












      4








      4





      $begingroup$



      Find $5$ numbers where the sum of the pairs gives the results $110, 112, 113, 114, 115, 116, 117, 118, 120, 121$




      I have been trying on this question for some time and it seems easy at first glance, but later on, I was unable to start on the question. I tried turning these into equations with $a_1, a_2, a_3, a_4, text{ and }a_5$ but couldn't as it is not determined which $2$ numbers give which sum. I was, however, able to achieve that $a_1+a_2+a_3+a_4+a_5=289$ (which is obvious). Now is there anyway I could continue without guessing. Thank you.










      share|cite|improve this question









      $endgroup$





      Find $5$ numbers where the sum of the pairs gives the results $110, 112, 113, 114, 115, 116, 117, 118, 120, 121$




      I have been trying on this question for some time and it seems easy at first glance, but later on, I was unable to start on the question. I tried turning these into equations with $a_1, a_2, a_3, a_4, text{ and }a_5$ but couldn't as it is not determined which $2$ numbers give which sum. I was, however, able to achieve that $a_1+a_2+a_3+a_4+a_5=289$ (which is obvious). Now is there anyway I could continue without guessing. Thank you.







      elementary-number-theory






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      asked Dec 8 '18 at 11:40









      user587054user587054

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          As there are no duplicates among the pair sums, the five numbers are distinct. So wlog. $a_1<a_2<a_3<a_4<a_5$. Then $110=a_1+a_2$, $112=a_1+a_3$, which makes $a_3=a_2+2$. Similarly, we find $a_4=a_3+1$ from the last two entries $120,121$. So far we have found that the numbers are
          $$a_1, a_2, a_2+2, a_2+3, a_5.$$
          This also tells us that $a_1+a_4=113$ and that $a_2+a_5=118$.
          Now that the three pair sums $a_2+a_3=2a_2+2$, $a_2+a_4=2a_2+3$, $a_3+a_4=2a_2+5$ must occur among $114,115,116,117$. The only possible match is that $a_2+a_3=114$, i.e., $a_2=56$. The rest follows easily from here.






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            1 Answer
            1






            active

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            1 Answer
            1






            active

            oldest

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            active

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            votes






            active

            oldest

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            5












            $begingroup$

            As there are no duplicates among the pair sums, the five numbers are distinct. So wlog. $a_1<a_2<a_3<a_4<a_5$. Then $110=a_1+a_2$, $112=a_1+a_3$, which makes $a_3=a_2+2$. Similarly, we find $a_4=a_3+1$ from the last two entries $120,121$. So far we have found that the numbers are
            $$a_1, a_2, a_2+2, a_2+3, a_5.$$
            This also tells us that $a_1+a_4=113$ and that $a_2+a_5=118$.
            Now that the three pair sums $a_2+a_3=2a_2+2$, $a_2+a_4=2a_2+3$, $a_3+a_4=2a_2+5$ must occur among $114,115,116,117$. The only possible match is that $a_2+a_3=114$, i.e., $a_2=56$. The rest follows easily from here.






            share|cite|improve this answer









            $endgroup$


















              5












              $begingroup$

              As there are no duplicates among the pair sums, the five numbers are distinct. So wlog. $a_1<a_2<a_3<a_4<a_5$. Then $110=a_1+a_2$, $112=a_1+a_3$, which makes $a_3=a_2+2$. Similarly, we find $a_4=a_3+1$ from the last two entries $120,121$. So far we have found that the numbers are
              $$a_1, a_2, a_2+2, a_2+3, a_5.$$
              This also tells us that $a_1+a_4=113$ and that $a_2+a_5=118$.
              Now that the three pair sums $a_2+a_3=2a_2+2$, $a_2+a_4=2a_2+3$, $a_3+a_4=2a_2+5$ must occur among $114,115,116,117$. The only possible match is that $a_2+a_3=114$, i.e., $a_2=56$. The rest follows easily from here.






              share|cite|improve this answer









              $endgroup$
















                5












                5








                5





                $begingroup$

                As there are no duplicates among the pair sums, the five numbers are distinct. So wlog. $a_1<a_2<a_3<a_4<a_5$. Then $110=a_1+a_2$, $112=a_1+a_3$, which makes $a_3=a_2+2$. Similarly, we find $a_4=a_3+1$ from the last two entries $120,121$. So far we have found that the numbers are
                $$a_1, a_2, a_2+2, a_2+3, a_5.$$
                This also tells us that $a_1+a_4=113$ and that $a_2+a_5=118$.
                Now that the three pair sums $a_2+a_3=2a_2+2$, $a_2+a_4=2a_2+3$, $a_3+a_4=2a_2+5$ must occur among $114,115,116,117$. The only possible match is that $a_2+a_3=114$, i.e., $a_2=56$. The rest follows easily from here.






                share|cite|improve this answer









                $endgroup$



                As there are no duplicates among the pair sums, the five numbers are distinct. So wlog. $a_1<a_2<a_3<a_4<a_5$. Then $110=a_1+a_2$, $112=a_1+a_3$, which makes $a_3=a_2+2$. Similarly, we find $a_4=a_3+1$ from the last two entries $120,121$. So far we have found that the numbers are
                $$a_1, a_2, a_2+2, a_2+3, a_5.$$
                This also tells us that $a_1+a_4=113$ and that $a_2+a_5=118$.
                Now that the three pair sums $a_2+a_3=2a_2+2$, $a_2+a_4=2a_2+3$, $a_3+a_4=2a_2+5$ must occur among $114,115,116,117$. The only possible match is that $a_2+a_3=114$, i.e., $a_2=56$. The rest follows easily from here.







                share|cite|improve this answer












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                answered Dec 8 '18 at 11:56









                Hagen von EitzenHagen von Eitzen

                282k23272507




                282k23272507






























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