I want to buy a $1.00 newspaper. I have just enough pennies $0.01, nickels $0.05, dimes $0.10, and quarters $0.25 to buy the newspaper in every possible exact-change combination of those coins.
How many coins do I have?
The question is not clear.
If I want to make any combination possible using pennies, nickels, dimes and quarters I would need:
= 134 coins.
But I do not think that is what you mean.
If you were offered a job for 30 days
starting at $0.01 the first day,
$0.02 the second day,
$0.04 the third day
and it doubled every day
like that for thirty days.
Would you take the Job and why?
You want to send a valuable object to a friend. You have a box which is more than large enough to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have. Note that you cannot send a key in an unlocked box, since it might be copied.
How is this done?
A lady just married a man. They do not have enough money to stay in a decent hotel. The couple stays with the man's mother. The man's mother has a jar full of lima beans, the lady's favourite food. The lady takes one lima bean each day they stay. The man's mother suspects the lady's theiving, but does not say a word. One day, the man's mother and wife are cleaning the kitchen together. The lady sees the man's mother looking at her eying the jar, now half full of lima beans. The lady finds one on the counter top and holds it up to the man's mother. She says three words that relieves the man's mother's suspection. What are those three words?