$1.$ Write a program in python to compute the volume and circumference of a sphere. The

user will ask for the radius as the input.

$2.$ Write a program to check if an input number$$s last digit is divisible by $7.$

$3.$ Write a program in python to swap the values of two variables. $[$If a$=5$ and b$=3$; after

swapping, a will become $3$ and b will become $5]$

$4.$ Write a program in python to check if an input number is divisible by both $3$ and $7$ or not.

$5.$ Write a program to create a calculator which performs addition, subtraction,

multiplication and division. The user will be given a choice from the number $1$ to $4$ for

the $4$ tasks. Based on the user$$s input $(1,2,3,4),$ one of the functions of the calculator will

be executed.