As you probably know, you can switch and mismatch the different terms in equations.
So since the equation for distance is d = r (or speed (s)) multiplied by time.
We can move speed to the other side of the equation by dividing it out.
I’ll be putting rate as speed instead btw.
d/s = t
Now we got the equation for time.
Just substitute and we get 765/85 = time, which is 9.
Answer: A. 9 hours