Answer: 15 miles
Step-by-step explanation:
2/3 of the way is 30 miles
Let x represent the total distance to grandmother's house, then
[tex]\quad \dfrac{2}{3}x=30\\\\\rightarrow 2x=90\\\\\rightarrow x = 45[/tex]
Since the total distance is 45 and they have already driven 30 miles, there is 15 miles to go
