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.
Remove 2 matchsticks from the stick puzzle figure of 8 triangles to leave 6 triangles. Now the second part of the puzzle, "How many solutions can you find?" Total Recommended time is 30 minutes. Go through the systematic solution only after you try. It'll be fun if you try first..
Find the 10 digit number with each digit different and each number formed by first n digits divisible by n. Step by step solution by basic math explained.
You are given 8 identical looking balls with one of the balls is fake and heavier or lighter than the other 7. You have to identify the fake ball in 3 weighing attempts. Given is a two-pan balance with no weights. In how many ways can you solve the puzzle?
You are given 8 identical looking balls with one of the balls slightly heavier than the other 7. You have to identify the heavier ball in 2 weighing attempts. Given is a two-pan balance with no weights. In how many ways can you solve the puzzle is the second harder part of the puzzle...
Three couples—king and queen, and minister and washerman with their wives have to cross a river in a boat that can carry at most 2 passengers at a time. The husbands are jealous and without her husband, no lady can be left on any side of the river with other male(s). To make matters worse, the washerman or washerwoman can travel together but not with anyone of the other two couples. Each of the six can row the boat...
This time Three humans, one big monkey and two small monkeys are to cross a river in a boat that can carry at most two, only the humans and the big monkey can row the boat and most alarmingly—at all times number of monkeys must not become more than the number of humans on any bank of the river, because in that case the monkeys will eat up the humans....
Two pigs and two hens must cross the river in a boat that starts for the opposite bank automatically when one of the four comes aboard. Constraint is—two pigs cannot cross the river in the boat together—it will sink....
Fox goose corn riddle: Farmer to cross river with fox, goose and corn in a boat that takes at most two. Fox eats goose and goose eats corn if left alone.
Move 3 matches to make 2 squares in 2nd matchstick puzzle of this type. How many unique solutions can you find? Recommended time 5 minutes. Try your hand. It will be fun...
