Jugs with Water

You have a 3 liter jug, a 5 liter jug, and an infinite amount of tap water. How can you measure exactly 4 liters of water using the jugs?

Call the 3 liter jug “small” the 5 liter jug “large”.

  • Fill the large jug with water.
  • Pour 3 liters of water from the large jug into the small jug.
  • Empty the small jug with water.
  • Pour the remaining 2 liters of water from the large jug into the small jug.
  • Fill the large jug with water.
  • Pour water from the large jug into the small jug, until the small jug is full.

Now there are exactly 4 liters of water in the large jug.

A Good Bet

Someone tells you: “I’ll bet you $1 that if you give me $3, I will give you $5 in return”. Is this a good bet?

You should not accept the bet and give him $3. If the person gives you the $5, then you would have given him $1+$3=$4, and you would make a profit of $1. However, the person can simply not give you anything and you will lose $3-$1=$2.

A Dream Man at a Funeral

While at her own mother’s funeral, a girl meets a guy she doesn’t know. She thinks the guy is amazing – her dream man – and is pretty sure he could be the love of her life. However, she never asks for his name or number and afterwards can not find anyone who knows who he is. A few days later, the girl kills her own sister.

Why did she do it?

The girl assumed the man was a family friend, so she decided he would come also to the funeral of her sister.