Jesse runs 0.13 miles per one hour.
She wants to run a total of 50 miles.
0.13 miles .... 1 hour
50 miles ... x hours
We would like to know how long this will take (x hours). You can calculate this in the following way:
0.13 * x = 50 * 1 /0.13
x = 50/0.13
x = 384.6153846153846154 (hours)
The result is 384.6153846153846154 hours.