Write a JavaScript function:

$2,3,5$

a$)$ to remove a part of a string from the beginning. Sample string: 'raghul@vit.ac$.$in$\text{'}$ Expected Output : $\text{'}$

vit.ac$.$in$\text{'}$

b$)$ to insert a string at the specified position in a given string.

Original String: 'The brown fox'

Insert 'quick' between 'The' and 'brown'.

Expected Output: 'The quick brown, fox'

c$)$ to generate a simple random password from a given string.

Sample string

:$\text{'}1234567890$ABCDEFGHIJKLMNOPQRSTUVWXYZabcefghijklmnopqrstuv

wxyz Note: Password length may be $6,7,8,$ etc