Answer: her mum drove for 12.67 hours and her dad drove for 12.67 hours
Explanation:
Her mom drove 75 miles an hour and her dad drove 60 miles an hour.
The ratio of her mum's speed to her dad's speed is 75 : 60
Total ratio = 75 + 60 = 135
Since the speed of her mum and her dad will determine the distance that each of them covered,
Distance covered by mum will be
Speed of mum/ total ratio × total distance covered. It becomes
75/135 × 1710 = 950 miles
Distance covered by dad would be total distance - distance covered by mum. It becomes
1710 - 950 = 760 miles
Time spent by her mum = distance covered by her mum / speed of her mum. This becomes
950/75 = 12.67 hours
Time spent by her dad = distance covered by her dad / speed of her dad. This becomes
760/60 = 12.67 hours