A student wanted to drive from Austin to
San Antonio, 80 miles south of Austin on
highway 135. Unfortunately, he entered the
highway in the wrong direction and drove all
the way to Waco 100 miles north of Austin
before he noticed his error. In Waco.
he turned around, drove back to Austin and
continued to San Antonio. The whole trip
took 7.22 h.
W
What was the student's average speed dur-
ing this trip?
Answer in units of mph.
XI