String

What is the output of the following code?
str1='Virtual PythonLab'str1[3]= 's'print(str1)?
What is the Output of the given string ?
str1='Virtual'str2='Python'str3=str1 + str2print(len(str3))
What arithmetic operators cannot be used with strings?
What is the output of 'virtual'+1+2+'python'?
5 If y='123' what will be the the return type of type(y)?