Logical Puzzles

21. The egg vendor calls on his first customer and sells half his eggs and half an egg. To the second customer he sells half of what he had left and half an egg, and to the third customer he sells half of what he had then left and half an egg. By the way he did not break any eggs. In the end three eggs were remaining.
How many did he start out with?
Answer
31 eggs.
22. I have collected 253 strawberries which I want to put into punnets for handing out to my neighbours. All punnets must contain the same number of strawberries and I wish to use as few punnets as possible. How many of my neighbours received a punnet of strawberries, and how many strawberries did each punnet contain?
Answer
11 punnets each containing 23 strawberries. 253 is the product of two prime numbers 11 and 23.