Question

the force of a bag of potatoes on a vegetable stand is 22.5 N down. what is the force of the vegetable stand on the bag of potatoes?

Answer 1

As per Newton's III law we can say that

Force applied by object 1 on object 2 is always equal in magnitude and opposite in direction of the force that object 2 apply on object 1.

So we can say it as

$F_{12} = -F_{21}$

now here above question is based upon the same

if a bag of vegetables applied a force F = 22.5 N of the surface stand the the same surface will apply same magnitude of force in opposite direction on the vegetables bag

So our answer will be F = 22.5 N (upwards).