If their average velocity is 55 mph Northwest, they won't arrive in Santa Fe.
First of all, the straight-line distance from Houston to Santa Fe is only 740 miles. And if the headed out from Houston going northwest and maintained that heading, then they passed about 135 miles north of Santa Fe.
Let's just work with SPEED, OK ?
If they drove 881 miles at an average speed of 55 mi/hr, then
the trip took them
(881 mi) x (hr / 55 mi) = 16.018 hours (16 hrs 1 min)
