Logic Riddles

Logic riddles with answers involve looking at situations and making judgements about them by ruling out impossibilities. If you like solving maths puzzles, you will most probably like logic riddles as well.

Getting Home with the Money

Johnny is walking home. He has $300 to bring home to his mom. While he is walking, a man stops him and gives him a chance to double his money.

The man says, “I’ll give you $600 if you can roll 1 die and get a 4 or above, you can roll 2 dice and get a 5 or 6 on at least one of them, or you can roll 3 dice and get a 6 on at least one die. If you don’t I get your $300.”

What does Johnny do to have the best chance of getting home with the money?

Riddle Answer

Poisonous Milk Bottle

You are trapped in a room with no food.

After 2 days, you are given 4 bottles of milk out of which one bottle is poisonous.

There is a rat in the room and to find out which bottle is poisonous you can feed milk samples to that rat. But the challenge is that the poison takes effect exactly 10 hours from feeding.

You have only 24 hours in your hand within which you must consume 3 bottles of milk to satisfy your hunger or else you will die.

What strategy would ensure that you drink 3 bottles of milk within 24 hours and survive?

Answer

Feed the rat with milk from one bottle every 1 hour. In this way, if the rat dies after 10 hours, then the first bottle is poisonous.

If the rat does not die after 10 hours, you can drink from milk from the first bottle.

Similarly, if the rat dies after 11 hours, then the second bottle is poisonous, if it dies in 12 hours, the third bottle is poisonous.

However, if the rat doesn’t die even after 12 hours, then the fourth bottle is poisonous and you need not test further.

In this way, you will need a maximum of 12 hours to drink 3 bottles of milk.