I got to writing this Prolog/constraint version which you can try on SWISH by clicking https://swish.swi-prolog.org/p/FYMhJEmj.pl https://swish.swi-prolog.org/p

I got to writing this Prolog/constraint version which you can try on SWISH by clicking https://swish.swi-prolog.org/p/FYMhJEmj.pl https://swish.swi-prolog.org/p/FYMhJEmj.pl then clicking the blue 'Run' button in the lower right corner. :-use_module(library(clpfd)). % score/3 has mode ++- and maps % a given answer and a correct answer to a score. score(Given, Correct, Score) :- zcompare(Order, Given, Correct), score_(Order, Score). score_(=, 10). % 10 points if given matches correct, score_(<, 0). % else 0 points score_(>, 0). puzzle(ColinTotal, ColinScores, CorrectAnswers) :- A = 0, % false B = 1, % true length(CorrectAnswers, 10), % ten unknown correct answers, CorrectAnswers ins 0..1, % all either true or false. % compare player answers with correct answers, add their scores. maplist(score, [B,B,A,B,A,B,B,A,B,B], CorrectAnswers, Mary), sum(Mary, #=, 70), maplist(score, [B,A,A,A,B,A,B,A,A,A], CorrectAnswers, Dan), sum(Dan, #=, 50), maplist(score, [B,A,A,A,B,B,B,A,B,A], CorrectAnswers, Lisa), sum(Lisa, #=, 30), maplist(score, [B,B,A,A,A,B,B,A,A,A], CorrectAnswers, ColinScores), sum(ColinScores, #=, ColinTotal). Then this query: ?- puzzle(ColinTotal, ColinScores, CorrectAnswers). Solves without a constraint solver search and gives four possible solutions, each giving the same score for Colin which I've aligned by hand for this comment: ColinTotal = 60, ColinScores = [10, 10, 10, 0, 10, 0, 10, 0, 10, 0], CorrectAnswers = [ 1, 1, 0, 1, 0, 0, 1, 1, 0, 1] ColinTotal = 60, ColinScores = [10, 10, 10, 0, 10, 0, 0, 10, 10, 0], CorrectAnswers = [ 1, 1, 0, 1, 0, 0, 0, 0, 0, 1] ColinTotal = 60, ColinScores = [10, 10, 0, 0, 10, 0, 10, 10, 10, 0], CorrectAnswers = [ 1, 1, 1, 1, 0, 0, 1, 0, 0, 1] ColinTotal = 60, ColinScores = [ 0, 10, 10, 0, 10, 0, 10, 10, 10, 0], CorrectAnswers = [ 0, 1, 0, 1, 0, 0, 1, 0, 0, 1] Questions 2,4,5,6,9,10 have a fixed correct answer and 1,3,7,8 can vary and the puzzle is still coherent and solvable.