Subscribe now

Read the original question

Answer: Twente beat Sporting; Sporting 9 points, Twente 5 points

The winner is Richard Kennaway of Norwich, UK. There were 77 entries.

Worked answer

There must be at least 4 points between successive teams. Total points gained after 5 weeks are 30 if no matches have been drawn, 29 if 1 has been drawn, 28 if 2 have been drawn, etc.

If R have 12 points, points scores must be R12, S8, T4, U0. This gives a total score of 12+8+4+0 = 24, requiring 6 drawn matches – impossible since neither R nor U can have drawn any. So R have 15 (5 w) or 13 (4w, 1d) points.

If R have 15 points, S have played R at least once and lost, so cannot have more than 10 points (3w, 1d, 11); in that case R and S have 25 points between them, and T can only have 4 points (1w, 1d, 31) and U 0 points (51): 15+10+4+0 = 29, with SvT the 1 drawn match.

If R have 15 points and S 9 points (3w, 21), T cannot have 5 points (1w, 2d, 21) because 15+9+5 = 29, which allows only 1 drawn match.

Nor can T have 4 points and U 0 points: 15+9+4+0 = 28, requiring 2 drawn matches; but with these points only T can have drawn a match.

Nor can the points scores be R15, S8, T4, U0: 15+8+4+0 = 27, requiring 3 drawn matches, but with these points neither R nor U have drawn any.

So if R have 15 points, the scores are R15, S10, T4, U0. R have won all 5 matches and S have lost only once, so RvS and TvU are outstanding. The results are:

(1) R beat S, R beat T (twice), R beat U (twice); S beat T, SvT drawn, S beat U (twice); T beat U.

If R have 13 points, points scores cannot be R13, S8/9, T4, U0 because 13+8/9+4+0 = 25/26, requiring 5/4 drawn matches – impossible since R have drawn only 1 and U haven’t drawn any. The number of drawn matches is manageable only if points scores are R13, S9, T5, U0/1.

With R13, S9, T5, U0, since 13+9+5+0 = 27, S must have drawn 3 matches; neither R nor S have lost, so RvS and TvU are outstanding.

(2) RvS drawn, R beat T (twice), R beat U (twice); SvT drawn (twice), S beat U (twice); T beat U.

With R13, S9, T5, U1 there must have been 2 drawn matches: RvT and TvU; there are 3 possibilities for the results so far, dependent on which matches are still outstanding:

(3) RvS, TvU outstanding: R beat S, R beat T, RvT drawn, R beat U (twice); S beat T, S beat U (twice); T beat S, TvU drawn.

(4) RvT, SvU outstanding: R beat S (twice), RvT drawn, R beat U (twice); S beat T (twice), S beat U; T beat U, TvU drawn.

(5) RvU, SvT outstanding: R beat S (twice), R beat T, RvT drawn, R beat U; S beat T, S beat U (twice); T beat U, TvU drawn.

The only unique results in the 5 possible sets are highlighted in bold:

RvS drawn in (2), T beat S in (3). Since the puzzle says that I would say who beat whom, it must be that T beat S as in (3). So S currently have 9 points and T 5 points.

Read the original question

Sign up to our weekly newsletter

Receive a weekly dose of discovery in your inbox. We'll also keep you up to date with New Scientist events and special offers.

Sign up
Piano Exit Overlay Banner Mobile Piano Exit Overlay Banner Desktop