"if it were possible" vs "if it was possible" [duplicate]

Solution 1:

"Was" is the "helper" for the "simple past" passive tense in the third person. Therefore, as the phrase "it was possible" is grammatically correct in simple past passive, you can use it.

However, it is also correct to use "were" in the "second conditional" for the first and third person singulars as well as the second person singular and all plurals. So in addition to "if you were" and "if they were", the phrases "if I were" and "if he/she/it were" are also correct.

So, short answer, they're both right in this case, because the usage of "was/were" as the past participle is both in the second conditional and in the past simple passive.