Magnetic force on moving charges

A region of uniform magnetic field makes a rectangular cross-section on the $x$‍-$y$‍ plane. The field points in the $-z$‍ direction (into the screen).

A $0.50\mu \text{C}$‍ point charge moves on the $x$‍-$y$‍ plane with a speed of $6.0{\displaystyle \frac{\text{m}}{\text{s}}}$‍. It experiences a force of magnitude $1.2\mu \text{N}$‍ the instant it enters the magnetic field.

What is the magnitude of the magnetic field?

$\text{T}$‍