To apply the techniques discussed in this chapter to real-world problems, it is necessary to translate these problems into questions that can be answered mathematically. the process of reformulating a real-world problem as a mathematical one often requires making certain simplifying assumptions. to illustrate this, consider the following snowplow problem: one morning it began to snow very hard and continued snowing steadily throughout the day. a snowplow set out at 9: 00 a. m, to clear a road, clearing 2 mi by 11: 00 a. m. and an additional mile by 1: 00 p. m. at what time did it start snowing? to solve this problem, you can make two physical assumptions concerning the rate at which it is snowing and the rate at which the snowplow can clear the road. because it is snowing steadily, it is reasonable to assume it is snowing at a constant rate. from the data given (and from our experience), the deeper the snow, the slower the snowplow moves. with this in mind, assume that the rate (in mph) at which a snowplow can dear a road is inversely proportional to the depth of the snow.