Suppose the Price of a Good Rises from $10 to $20

Multiple Choice

Suppose the price of a good rises from $10 to $20 and quantity demanded falls from 500 to 400. If you calculate the elasticity of demand WITHOUT using the midpoint method, the answer would be _____. If you calculate the elasticity of demand WITH the midpoint method, the answer would be _____. Economists say _____ when calculating elasticity.

A) -1/2; -1/3; use the midpoint method
B) -1/3; -1/5; do not use the midpoint method
C) -1/4; -1/4; it doesn't matter which method you use
D) -1/5; -1/3; use the midpoint method