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0 / 60 seg.
Why is a manhole round? Why is it better to have round manhole covers compared to square manhole covers?
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Clue
YOU'D BE ASSURED OF A PAIR OF BLACK SOCKS BY PULLING 26 SOCKS. ALTHOUGH THE CHANCES ARE REMOTE, YOU JUST MIGHT PULL THE 24 BLUE SOCKS OUT FIRST. YOU'D NEED TWO MORE TO MAKE CERTAIN TO GET TWO BLACK SOCKS
I DO NOT HAVE ANY DAUGHTERS AND THE TRUE STATEMENT IS: I HAVE LESS THAN TEN DAUGHTERS. IF I HAVE ANY DAUGHTERS, THERE WILL ALWAYS BE TWO STATEMENTS WHICH ARE TRUE. THEREFORE, I HAVE NO DAUGHTERS
A = 3.5 B = 4.5 C = 9.5 D = 3.5 TO SOLVE THE PUZZLE, YOU WILL NEED TO COME UP WITH 4 EQUATIONS: A + B = 8 ... (1) C - D = 6 ... (2) A + C = 13 ... (3) B + D = 8 ... (4) SUBTRACTING (1) FROM (3) GIVES: C - B = 5 ... (5) ADDING (2) TO (4) GIVES: B + C = 14 ... (6) ADDING (5) AND (6) GIVES: 2C = 19 C = 9.5 SUBSTITUTING C = 9.5 IN (2) GIVES: 9.5 - D = 6 D = 3.5 SUBSTITUTING D = 3.5 IN (4), GIVES: B + 3.5 = 8 B = 4.5 SUBSTITUTING B = 4.5 IN (1), GIVES: A + 4.5 = 8 A = 3.5
A SQUARE MANHOLE COVER CAN FALL INTO THE MANHOLE AS THE DIAGONAL LENGTH OF A SQUARE MANHOLE IS GREATER THAN THE SIDES. A ROUND MANHOLE COVER CAN NEVER FALL INTO THE MANHOLE
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