At a price of $4 per unit, Gadgets Inc. is willing to supply 20,000 gadgets, while United Gadgets is willing to supply 10,000 gadgets. If the price were to rise to $8 per unit, their respective quantities supplied would rise to 45,000 and 25,000. If these are the only two firms supplying gadgets, what is the elasticity of supply in the market for gadgets?