We didn’t go by air because we didn’t have enough money.
If we would go by air, we had enough money.
We would go by air if we had enough money.
We had enough money if wewould have gone by air.
We would have gone by air if we had enough money.
Correct Answer: EASY
Conditional sentence type 3 is used to express an impossible possibility in the past
If + S1 + had+ P2…, S2 + would + have + P2…
We don’t take the plane because we don’t have enough money.