Electron beam path with perpendicular magnetic fields of 0.1mT and 1.0mT

[strawberrysk8]

Homework Statement

The original direction of the electron beam as it enters the magnetic field is along the earth’s magnetic field. If the magnitude of the earth’s magnetic field is 0.1 mT and the magnetic field due to the Helmholtz coils is 1.0 mT (perpendicular to the electron beam), the resulting path of the electron can be best described as:

Homework Equations

I have no idea where to begin.

The Attempt at a Solution

I guessed it would be circular but that is wrong.

 

[Defennder]

Uh, where did the Helmholtz coils come into the picture? Is this the question in its entirety?