4 from 3 and 5

Question: You were given two cans one is of 3litre capacity other with 5 litre capacity and asked to provide with 4 litres of water.(we can do anthing like pour the water away supply of water to you is unlimited)

Solution:

1. Fill the 3-liter bottle and pour it into the empty 5-liter bottle.
2. Fill the 3-liter bottle again, and pour enough to fill 5-liter bottle. This leaves exactly 1 liter in the 3-liter bottle.
3. Empty the 5-liter bottle; pour the remaining 1 liter from the 3-liter bottle into the 5-liter bottle.
4. Fill the 3-liter bottle and pour it into the 5-liter bottle. The 5-liter bottle now has exactly 4 liters.