Jennifer and katie are leaning on each other. jennifer weighs 150 and katie weighs 120. which one is pushing harder on the other?

They're just standing there, not going anywhere. Definitely not accelerating. That tells us that the net force on each one must be zero. So whatever push Katie is giving, she must be getting one the same size from Jennifer. And the same goes for the other lady.

What ever push she's giving her friend, her friend is also giving her.

Somehow, they're both pushing with equal forces.

that would be because of both gravity and friction. so     c

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards