Guest Posted December 24, 2009 Report Share Posted December 24, 2009 Determine all possible octuplet(s) (P, Q, R, S, T, U, V, W) of positive integers, with P ≤ Q ≤ R ≤ S, and T ≤ U ≤ V ≤ W, and P < T satisfying: P+Q+R+S = T*U*V*W and, P*Q*R*S = T+U+V+W. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 25, 2009 Report Share Posted December 25, 2009 For given conditions. If P>2 , P+Q+R+S < P*Q*R*S Since T> P, T+U+V+W < T*U*V*W If P*Q*R*S=T+U+V+W then P+Q+R+S < T*U*V*W. For P=1, I could not find any solution. Narendra Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 26, 2009 Report Share Posted December 26, 2009 (edited) For given conditions. If P>2 , P+Q+R+S < P*Q*R*S Since T> P, T+U+V+W < T*U*V*W If P*Q*R*S=T+U+V+W then P+Q+R+S < T*U*V*W. For P=1, I could not find any solution. Narendra You are right, NS. Looking back at the original post, I have detected a typographical lacuna in the second line - where, in place of the condition P < T, it should have been, P <= T. In view of the maximum time limit of 10 minutes for any given submitter to correct his original post, I visualize no succinct avenue to incorporate the said amendment in the OP. Edited December 26, 2009 by K Sengupta Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 26, 2009 Report Share Posted December 26, 2009 (edited) Ok I could not find a solution for P < T either but First let me say that I used a brute force approch to this so I may not have all of them as I limited the numbers to <=10. I know thats a small number but the number of permutations was already 100000000 and using numbers <=11 more than doubles the permutations. In narendrasony's post it was concluded that there are no solutions for P < T so it seems that you could set P = T of which I found 3. P Q R S T U V W 1 1 1 9 1 1 3 4 Both sides + and * to 12 1 1 2 4 1 1 2 4 Both sides + and * to 8 1 1 3 4 1 1 1 9 Both sides + and * to 12 and it is the same as the first with PQRS switched with TUVW Edit: spelling errors Edited December 26, 2009 by stewdeker Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 26, 2009 Report Share Posted December 26, 2009 If P=T then one of the quadrapulets (say P,Q,R,S) should satisfy : P+Q+R+S >= PQRS. This can be true iff P=1 and Q=1 (verify for Q>1 this is not true). So the possible solutions are (P,Q,R,S), (T,U,V,W): a) (1,1,2,4), (1,1,2,4) b) (1,1,1,9), (1,1,3,4) c) (1,1,1,11), (1,1,2,7) First two are already mentioned by Stewdeker. Quote Link to comment Share on other sites More sharing options...
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Determine all possible octuplet(s) (P, Q, R, S, T, U, V, W) of positive integers, with P ≤ Q ≤ R ≤ S, and T ≤ U ≤ V ≤ W, and P < T satisfying: P+Q+R+S = T*U*V*W and, P*Q*R*S = T+U+V+W.
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