Question 915718
In this problem you will need to start with equations.  
Lets start with the equations:  

The basic formula we are using is  Distance = Rate* Time or D=R*T

The First sentence tells us that the distance is 10.  So the first equation by this sentence is 10 = RT.  

The second sentence tells us about the second equation.  The Rate is doubled. 
We represent that by 2R instead of R.  It also says that the time is one hour less represented by T-1.    The second equation would then be 
10 = 2R * (T-1)  

Since both Equations have are equal to 10,  we can set them equal to each other.  Normally we would have to do  either use substitution or elimination with the equations. 

RT = 2R(T-1)

RT/R = 2R(T-1)/R
T = 2(T-1)
T = 2T-2
T = 2
10= RT
R = 5