Question

Alexander is riding his bicycle to school. After one mile he is a third of the way there. How much more does he have to ride

Answer 1

If the question unit is miles, then he has 2 miles to go, the trip total is 3 miles.

Answer 2

You are given
  1 mile = (1/3)*(distance to school)
Multiply this equation by 3 and you have
  3 mile = (distance to school)

You also know that
  (distance ridden so far) +(remaining distance) = (distance to school)
Subsituting given information, this is
  1 mile + (remaining distance) = 3 mile
Subtracting 1 mile from this equation gives
  (remaining distance) = 2 miles

Alexander has 2 miles more to ride.