Marla begins walking at 3 mi/h toward the library. Her friend meets her at the halfway point and drives her the rest of the way to the library. The distance to the library is four miles. How many hours did Marla walk?
Half the distance. They said so. The walking speed does not matter.
Marla walked 2 miles at 3 miles/hour.
so her time walking was 2/3 hours or 40 minutes
To find out how many hours Marla walked, we can use the distance formula:
Distance = Speed x Time
Given that Marla's walking speed is 3 mi/h and the total distance to the library is 4 miles, we can break down the journey into two parts.
Let's denote the distance Marla walks as "x" miles.
Marla walks x miles at a speed of 3 mi/h, so we have the equation:
x = 3t, where t represents the number of hours she walks.
Next, let's determine the distance her friend drives. Since the total distance is 4 miles and they meet at the halfway point, her friend drives the remaining distance of 4 - x miles.
Given that her friend drives at a faster speed, we can assume she doesn't spend any time driving this remaining distance. Thus, we can say:
4 - x = 0t
Solving the second equation for "x":
4 - x = 0
x = 4
Now, we substitute the value of x back into the first equation to solve for t:
4 = 3t
t = 4/3
Therefore, Marla walks for 4/3 hours, or 1 and 1/3 hours, to reach the library.