Please tell how to solve Q 11 part a

Dear Student,
Diameter of the neck is = 2 cm = 0.02 m

So, area of cross-section of the neck is, a = πd²/4 = 0.000314 m²

Diameter of the bottom is = 10 cm = 0.1 m

So, area of cross-section of the bottom is, A = πd²/4 = 0.00785 m²

Force applied to the cork, f = 1.2 kgf

Let F be the force at the bottom, so,

F/A = f/a

=> F = (f/a)A = (1.2/0.000314)(0.00785) = 30 kgf
Regards