Answer: it will take them 15 hours to drive 750 miles.
Explanation:
The chamois are traveling from Arizona to Texas. On the first leg of the trip, they drove 500 miles in 10 hours.
Speed = distance covered/ time
Time = distance covered/speed
Speed during the first leg of the trip would be
500/10 = 50 miles per hour
If they continue driving at the same rate, then the time it will take them to drive 750 miles would be
750/50 = 15 hours