Question

It is much easier to burst
a balloon with needle than a finger. Why?

Answer 1

as the tip of the needle is very thin and covers less surface area than a finger it is easier to burst a balloon with needle

Answer 2

This is due the pressure applied.
pressure is inversely proportional to area.

Area of finger is larger than the needle..
thus the pressure applied is less

needle is pointed and has quite less area thus max pressure is applied and balloon gets burst.

hope this helps you. :)