Originally posted by DoctorScribbles
Who can remember the last time an interesting and challenging puzzle or problem was posted in this forum?

Easy...see "Another Magic of Logic", started by ranjan sinha.

Originally posted by BigDoggProblem
Easy...see "Another Magic of Logic", started by ranjan sinha.

I would also recommend the following two puzzles in this category:
(a) The puzzled titled " Counting Problem" created by Acolyte { which was about finding a bijection ( one to one mapping) between the set I of integers and the set Q of rationals}.
(b) The " Puzzle of syntax -why only one..." created by rspoddar82, which was about filling in the blanks of a sentence with numbers written in words so as to make the two sentences correct. The second part of that puzzle is as yet unsolved. I had submitted a mathematically correct solution to the second part, but that was dubbed as wrong due to grammatical & syntactical reasons. It was stipulated that the sentence must be both mathematically and grammatically correct.

Originally posted by ranjan sinha
I would also recommend the following two puzzles in this category:
(a) The puzzled titled " Counting Problem" created by Acolyte { which was about finding a bijection ( one to one mapping) between the set I of integers and the set Q of rationals}.
(b) The " Puzzle of syntax -why only one..." created by ...[text shortened]... as stipulated that the sentence must be both mathematically and grammatically correct.

"Triangle Puzzle" posted by THUD and BLUNDER was also a challenging and beautiful one.