The Colorado Department of Transportation oversees snow removal in Colorado. Still, this task is performed by private companies that use a sand/salt mixture that works as freezing-point depressants. The monthly inverse demand for sand/salt mixture is P = 90 1/10 Q, where the price is measured in dollars and quantity in tons. The sand/salt mixture market is perfectly competitive, and the price (inverse supply) is equal to $20 per ton: P = 20