A toll bridge carries 5000 vehicles per day when the toll is $1.50/vehicle. It is estimated that when the toll is increased by 25 cents, the traffic on the bridge will decline by 10% of the current volume. What is the toll that should be charged if it is desired to maximize the amount of money collected from motorists? I was able to figure out the equation for volume in terms of cost but wasn't able to figure out the cost equation in terms of volume.