A Gaint Ship's Engine was failed.

The Owners tried to 1 Expert to another

but non could fix the engine.

At last an Oldman was consulted who examined throughly the Owners' Presence.

Then He took out his Hammer and Tapped something.

The Engine Started instantly..

A week later Owners received a Bill for $ 10,000.

"What, He did nothing!" They Exclaimed and asked for the 

Detailed Itemized Bill.

They Got Detailed Bill as:

Tapping with Hammer= $1

Knowing where the Tap= $9999

= $10,000...:-)