This question in incomplete, therefore, I cannot provide an exact answer.
However, I'll tell you how to solve it and you can apply on the given numbers.
We have:
F = m * a
where:
F is the force
m is the mass
a is the acceleration
From this formula, we can note that at constant force, the mass of the body is inversely proportional to its acceleration. This means that as the mass decreases, the acceleration increases and vice versa.
Now, applying this concept to the given problem, we will find that:
The force applied is constant
Therefore, the wagon that will accelerate faster is the wagon with less mass.
Hope this helps :)