Exercise : Variable mutation

Suppose you have a variable named balance, set to 463.23:

double balance = 463.23

Suppose later in the program's code, we want to add 5 to the account balance. Which is a correct statement to do this?

1. balance + 5;
2. balance = 5;
3. balance = balance + 5;
4. 5 + balance = balance;
5. balance <-- 5;