Step-by-step explanation:
This sentence represents a past unreal conditional, also known as the third conditional. The reason is that it describes a situation that did not happen in the past, and imagines a different outcome if things had been different.
This sentence represents a first conditional, also known as a real conditional. The reason is that it describes a possible future situation and the result that may happen if the condition is met.
This sentence represents a second conditional, also known as an unreal conditional. The reason is that it describes a hypothetical situation or a condition that is not true, and imagines a result that could happen if the condition were true.