Which statement$($s$)$ is$/$are not true?

You can declare multiple variables with the same name if they are different types

A variable name can not start with a number

If you convert the double value $9\mathrm{.}99$ to an int, you will get $9$

You can not change the name of a variable after you have declared it$.$

Var$\_1$ and var$\_1$ are the same variable