smc

Question

Driving at a constant speed, Sharon usually takes 180 minutes to drive from her house to her mother's house. One day Sharon begins the drive at her usual speed, but after driving 13 of the way, she hits a bad snowstorm and reduces her speed by 20 miles per hour. This time the trip takes her a total of 276 minutes. How many miles is the drive from Sharon's house to her mother's house?

Accepted Answer

Let total distance be x. Her speed in miles per minute is x180. Then, the distance that she drove before hitting the snowstorm is x3. Her speed in snowstorm is reduced 20 miles per hour, or 13 miles per minute. Knowing it took her 276 minutes in total, we create equation: Time before Storm, + , Time after Storm = Total Time Distance before StormSpeed before Storm + Distance in StormSpeed in Storm = Total Time x3x180 + 2x3x180 - 13 = 276 Solving equation, we get x=135 135.