Geetanjali Express, which is $250$ metre long when moving from Howrah to Tatanagar crosses Subarnarekha bridge in $30$ seconds. What is the speed of Geetanjali Express?
Statement I: Bombay Mail, which runs at $60$ km/hour crosses the Subranarekha bridge in $30$ seconds.
Statements II: Bombay Mail when running at $90$ km/hour crosses a lamp post in $10$ seconds.