Question 118934
Let the motorcycle ride for x hrs and the rider walk for y hrs.

Then as we know total distance travelled is 25 miles and rider is traveling at 6 mi/hr and motorcycle at 45mil/hr we can have equation as 
45x+6y=25----(i)

now as total duration of trip is 2 hrs, x+y=2---(ii)

Thus we get two equations and we need to find two variables.

multiplying equation (ii) by 6 we get 6x+6y=12---(iii)

subtracting equation iii from equation (i) we get 39x=13 or x=1/3 

Substituting value of x in equation (ii) we get y=5/3.

Thus total miles covered by motorcycle is 45x= 45*(1/3)=45/3=15 miles.

Thus ans is 15 miles.