How much time would it take to crack time mnemonic phrases in these scenarios? How long time would it realistically take to crack each of following scenarios and how many combinations does each scenario consist of? 

Mnemonic Phrase, it is not known if we are looking for a pass-phrase of 12, 13, 24 or 25 words

Scenario 1: There are total 90 words shown on a single sheet of paper.

Scenario 2: There are total 180 words shown on two sheets of paper (90 each). It is not known how many words (of pass-phrase) are on each sheet of paper (meaning one sheet could have 0 and the other all)
You can calculate the number of word combinations for each possible pass phrase length and then add them together. For mnemonic phrases any order is valid, so it is a question of calculating the exponentiation of the number of words on the sheet with the number of words in the phrase.

Finally, there are two scenarios, which should be considered separately. For the first scenario there is just a single sheet of 90 words. For the second there are two sheets, but as the words do not need to be distributed over the sheets you can simply think of it as one sheet of 180 words.

Finally, if you want to know the number of bits of security you can simply count the number of digits, divide by 3 and then multiply with 10 to get a rough estimate (or perform $\log(c) / \log(2)$ where $c$ it the total number of combinations).