Q:

Hydrostatic pressure is equal everywhere, however, the answer I'm getting is incorrect

Question:

A hydraulic car lift has a pump piston with radius 0.015 m and a
  resultant piston with radius 0.120 m. The combined weight of the car
  and the plunger is 2500 N. Assume that the height of the piston and
  plunger are the same.
What amount of force (in N) is required on the pump piston to
  stabalize the car?

My try at it:
Since the heights of the piston and plunger are the same, so, the pressure on the car lift and resultant piston wil be the same, therefore, Pressure on the car = Pressure on the resultant piston.
=> F/A = F/A
=> 2500 N / 0.015 = x N / 0.120
Calculating this, I got x = 20,000 N, however, it is incorrect, what am I doing wrong?
Thanks.

A:

Here the radius of the pump piston according to your question is 0.015 m.
So the area of the pump piston is πr^2=π(〖0.015)〗^2= A(say)
If x N force require then we create pressure on that piston  is P= F/A=x/(π〖(0.015)〗^2 ).
Hence,
             F/A=x/(π〖(0.015)〗^2 )=2500/(π〖(0.12)〗^2 )
                   or, x= 39.06 N.

