In Liar, Truth-teller, Random-Answerer Riddle, a traveler can ask two questions to decide which is the safe path out of two. What to ask?
In liar and truth-teller riddle, to know the safe path, a traveler can ask only one question to any one of a habitual liar or a truth-teller. What to ask?
The 7 squares matchstick puzzle: Move 2 matches to make 7 squares in the puzzle figure. Time 10 mins. Apply reasoning based on matchstick puzzle concepts.
12 balls weigh 3 times to find the one fake. All 12 balls look same and you have a pan balance with no weights. Time to solve the 12 balls puzzle 40 mins.
Find the fake ball among 9 balls in 3 weighs. All balls look alike. You have a pan balance with no weights. Time to solve is 30 minutes.
Move 2 matches to form 5 matchstick shapes of squares, triangles or rhombuses. How many such new figures can you make? Total recommended time 10 minutes.
Move 1 stick to make 4 matchstick shapes of triangles, squares or rhombuses. How many such new figures can you make? Recommended time 10 minutes.
How to make 4 triangles with 6 sticks! Add 3 matches to the single matchstick triangle and make 4 triangles with 6 sticks. Time to solve 5 minutes. Can you?
Two Exponent and base puzzles: Both exponent and base of the term in LHS are quadratic equations in single variable and it equals 1. Time to solve 15 mins.
World's hardest easy geometry problem is to be solved by elementary geometry only and that makes it hard. Hint: Increase symmetry in the puzzle figure.
