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Two boxes are sliding toward each other on a friction-less table with initial conditions given in the image.

What is the magnitude of the momentum of this two object system?

$100\ \mathrm{kg\cdot m/s}$

$240\ \mathrm{kg\cdot m/s}$

$140\ \mathrm{kg\cdot m/s}$

$340\ \mathrm{kg\cdot m/s}$