Molly walks to raven's house, which is 3 miles due east of her house. then she and raven walk to the library, which is 4 miles due north of raven's house. molly then walks home. if she averages walking 3 miles per hour, how long does molly spend walking?

4 hours

Step-by-step explanation:

First we find the distance between the library and Molly's house.

The line segment from Molly's house to Raven's house, 3 miles, and the line segment from Raven's house to the library, 4 miles, form the legs of a right triangle.  Using the Pythagorean theorem,

a²+b²=c²,

3²+4²=c²

9+16=c²

25=c²

Take the square root of each side:

√(25) = √(c²)

5 = c

This makes the total number of miles Molly walks

3+4+5 = 12 miles.

Since she travels 3 miles per hour, she travels 12/3 = 4 hours.