Indian rupee security features

1.Hidden portrait of Mahatma Gandhi and a numerical number of the denomination of the note(1000 seen in a 1000Rs note). These two are seen when viewed against light.

rubik's cube - how to solve step by step illustration

I have learned to solve the rubik's cube and I have given a video in this link. There are English subtites also.
http://www.youtube.com/watch?v=RJUAqIwYhfM

How to remove mercury from gold ornaments(jewellery)?

Mercury when exposed to gold makes a amalgam of mercury which is a silver in color. The mercury may have accidentally fallen on to the ornaments from a thermometer,BP apparatus etc. DO NOT PANIC,