The smaller mass would travel faster.
Using the formula force = mass*acceleration, you can plug in different variables to test out which mass has a greater acceleration:
F=ma
Small mass: m1=1 kg
Large mass: m2=2 kg
Force: F=3 N
Acceleration for small mass:
3=1a
a=3 m/s^2
Acceleration for large mass :
3=2a
a=1.5 3m/s^2
Since the large mass has a lesser acceleration, the small mass (with a greater acceleration) would travel faster.