with what force would a boy have to push on the hole with his thumb to stop a leak?

Question

hole of area is 1.1^2 at a depth of 1m below the water surface

Answer 1

1.1^2 of what? I hope you meant cm
I'm assuming that A=1.1cm^2

Pressure P is
P=gph
g- acceleration due to gravity
p - density of water
h - depth

F=P A
F=g p h A
F= 9.81 x 1000 x 1 x 1.1 E-4=
F=1.1N