Lily runs a convenience store near her house.

One of the most popular products is the "Summer Paradise" Ice cream cone.

The product was sold out two weeks ago, in anticipation of a hot summer month.

Lily sold 150 cones last year, at a price of $60 per cone. Lily estimated that the price elasticity of the annual demand for the "Summer Paradise" Ice cream cone is given by:

= -p/(250-p)

where p is the price per cone and p < 250.

Calculate the annual demand for the product (in cones) when the price is $50 per cone.