the complete question in the attached figure
see the attached drawing to better understand the problem
Part A)
we know that
Area small piston=0.0020 m²
Force=100 N
[Pressure]=[Force]/[Area]
[Pressure]=[100 N]/[0.0020 m²]=50000 Pa
the answer part A is 50000 Pa
Part B)
Pressure=50000 Pa
Area large piston=3.14 m²
[Force]=[Pressure]*[Area}
[Force]=50000 Pa]*[3.14 m²]=157000 N
the answer part B) is 157000 N