A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.
After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.
Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?
John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3
Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?
In 2011, people playing Foldit, an online puzzle game about protein folding, resolved the structure of an enzyme that causes an Aids-like disease in monkeys. Researchers had been working on the problem for 13 years. The gamers solved it in three weeks.