Economics
posted by Randy .
The question is, what is the for Math formula to show rather the demand of apples is Elastic, Inelastic, or Unitary Elastic
Thank You
Suppose the price of apples rises from $3.50 a pound to $4.00 and your consumption of apples drops from 30 pounds of apples a month to 20 pounds of apples. Calculate your price elasticity of demand of apples. What can you say about your price elasticity of demand of apples? Is it Elastic, Inelastic, or Unitary Elastic? Be sure to show the work.

If the percent drop in consumption exceeds the percent increase in price. the demand is elastic. That is the case in your example.
See
http://en.wikipedia.org/wiki/Price_elasticity_of_demand 
Could you please show me the workout on this ? Thank You

Price elasticity is the percentage change in price divided by the percentage change in quantity.
%change in P = 100*(.50/3.50) =14.29
%change in Q = 100*(10/30) = 33.33
Elasticity therefore is 33.33/14.29 = 2.33
Since elasticity is > 1 (absolute value) it is elastic.
(Note: some economists prefer the midpoint method for calculating percentage change. here %change P is .5/3.75 and %change Q is 10/25). 
Thank You :)