That's a pretty confusing one. I think it's 10 minutes.
We know that speed * time = distance
Before we start we need to make sure the units for all three numbers are right
The time is 1/3 of a hour, 1/3*60 = 20 minutes
x * 20 = 22.5
x *2 * 10 = 22.5
2x = 2.25
x = 1.125