My aunt and I were approaching the same intersection, she from the south and I from the west. She was traveling at a steady speed of 9 miles/hour, while I was approaching the intersection at 50 miles/hour. At a certain instant in time, I was one-tenth of a mile from the intersection, while she was seven-twentieths of a mile from it. How fast were we approaching each other at that instant? (Give your answer to the nearest integer.)

Answer should be in mph.