Calculate the magnitude of the normal force acting on a 20 kg block the block is resting on the surface of an elevator accelerating 2.5m/s

Fn = 246.2 N

Explanation:

I assume you meant meters per second squared for acceleration of the elevator.  All you have to after your picture/free-body diagram is made is add the forces together.  You could do this by finding them separately like I did or use Fn = m(Fg + Fe). I just calculated magnitude and didn't worry about signs.

i think the answer is a and b

i wish you luck