By algebraically manipulating the algorithm for the 5x5 case, to score 10 points, you need to spend 1575 or more seconds solving the puzzle. That is 26.25 minutes. A higher total time gives you a score of 10 as 10 is the minimum points awarded for a finished 5x5 puzzle. Applying the same analysis to the 4x4 algorithm, to score 10 points, you need to spend 1095 or more seconds solving the puzzle. Again, the minimum score is 10 points, no matter how long it takes. 1095 seconds is 18.25 minutes, which fits your time frame. I know it seems impossible to solve quickly, but if you persevere and work hard, the puzzles will begin to make sense and your scores will rise. Keep trying...
