A mold grows at a rate that is proportional to the amount present. Initially there is 5 oz of this mold, and 10 hours later there is 7 oz. When is there 15 oz of the mold? (Answer is in hours.)

Find the intensity of light at a depth of 12 meter if I0=14 and k=0.7. Round to two decimals.

The resistance of a copper wire carrying an electrical current is directly proportional to its length and inversely proportional to its cross-sectional area. A copper wire with a diameter of 0.0126inch has a resistance of 64.9ohms per thousand feet. What length of 0.0201-inch-diameter copper wire will produce a resistance of 33.5ohms?

How much stock per stroke is removed by the wheel of a surface grinder if a depth of 4.725 millimeters is reached after 75 strokes? Round the answer to 3 decimal places.