OG详解-OG2 数学2 Q2

Choice A is correct. Since Jay walks at a speed of 3 miles per hour for w hours, Jay walks a total of 3w miles. Since Jay runs at a speed of 5 miles per hour for r hours, Jay runs a total of 5r miles. Therefore, the total number of miles Jay 
travels can be represented by 3w +5r. Since the combined total number of miles is 14, the equation 3w +5r =14 represents this situation.
Choice B is incorrect and may result from conceptual errors. Choice C is incorrect and may result from conceptual errors. Choice D is incorrect and may result from conceptual errors.