Can someone with number 5? will give brainliest to beat answer!

If an object is NOT round, then it is NOT a ball

Switching the hypothesis and conclusion of a conditional statement and negating both. For example, the contrapositive of "If it is raining then the grass is wet" is "If the grass is not wet then it is not raining." Note: As in the example, the contrapositive of any true proposition is also true. So the answer is "If it is not a ball, then the object is not round".

8doors on the second floor