A local pub recently raised its price of a draft beer from $4 to $6. As it did, the number of beers it sold decreased from 6,000 to 4,000 per month of this particular brew.

What will be the price elasticity of demand for the beer if the pub lowered the price from $4 to $2 per month and the quantity increased from 6,000 to 8,000?

How much did the pub's Total Revenue (TR) change as it lowered its price?