crossed helical gears

Question

1. The following are the data for two crossed helical gears used for speed reduction:

Gear I: Pitch circle diameter in the plane of rotation 80mm and helix angle 30⁰

Gear II: Pitch circle diameter in the plane of rotation 120mm and helix angle 22.5⁰

If the input speed is 1400 rpm. The output sped in rpm is                                                                                        

      (a) 1200                                                              (b) 900

      (c) 875                                                                (d) 720