Let the diameter of wheel B be ' $\(2 x\)$ ', so its radius is half of the diameter i.e. ' $\(x\)$ '
Now, the diameter of wheel A being half of the diameter of wheel B is ' $\(x\)$ ', so its radius is $\(\frac{x}{2}\)$

So, the distance covered by wheel B in one revolution must be double the distance covered by wheel A in one revolution.

Finally the number of revolutions that wheel A would take to cover 2500 miles would be same as the number of revolutions that wheel B would take to cover double distance i.e. 5000 miles.