1) A storm at sea has damaged an oil rig. A thin coat of oil spills from the rupture at a constant rate of 60 ft^2/min, forming an oil slick that is roughly circular in shape. How fast is the radius of the slick increasing when the radius is 70 feet?

2) When the price of a certain commodity is p dollars per unit, the manufacturer is willing to supply x hundred units, where 3p^(2)-x^(2)= 12. How fast is the supply changing when the price is $4 per unit and is increasing at the rate of 87 cents per month?

3) The top of a 5-foot ladder is sliding down a wall at the rate of 10 feet per second. How fast is the base of the ladder sliding away from the wall at the instant when the top of the ladder is 3 feet from the ground?