Ganapathi and Brain Yoga

Every year about August majority of hindus celebrate the festival of Ganesh chaturthi attributed to the ubiquitous elephant god. Hindus worship the god, primarily, to overcome obstacles and for a sharper intellect. This is one festival I look forward to every year. Partly because of associated fond memories, and, the unique offerings made to the god. Part of the ritual of the puja, is offering the god some situps. The situps are done holding the ear lobes with two fingers and the hands crossed in front.
The situps-holding-your-ears is an age-old disciplinary action followed by teachers & parents for erring wards. I do not know why the past generations chose to do this or how it came to be associated with ganapathi puja, and I wonder if they knew it was really beneficial in any way for the performer.
But now there is a lot of content on the web calling this super brain yoga. Just search for "Brain Yoga".

A Cool Puzzle

Here is a cool puzzle. Dont remember where I came across this one. All credit to its original author. It goes something like this.
5 Mathematicians and one wise man caught in enemy territory.They have half an hour to device a strategy to solve a problem failing which they all die. The problem...
The 5 mathematicians are made to stand in a circle. A hat is put on each one's head that carries a number between 1 and 9, including the extremes, on it. They cannot communicate in any way what so ever else they all get hanged. The wise man has two coins one Blue and one Red. After the hats are placed on each mathematician's head, the wise man can walk in and handover one coin out of the two to one person of his choice and walk away. After that, the enemy picks one (any) mathematician in the circle at random and asks the number on his head. If he is correct all live else all die.
What is the strategy that saves their lives?

• A number can be repeated
• One mathematician in the circle can see all the other 4 numbers.