About Minna no Nihongo I

So, I’m having an exam in 2 days and I need to study 4/5 lessons of Minna no Nihongo I. Problem is, I never got in touch with the book, having used Genki for the past year (as well as other methods for Kanji and vocabulary).

I wanted to plan things out with my other exam for the same day.

I come to ask those who used the book before or are currently using it – How long did it take you, on average, to complete each lesson?

PS: I know it’s impossible to give a certain ammount of time, but for insight, I tend to memorise grammar points and conjugations at a somewhat fast rate. Vocabulary is the hardest for me.

Thank you for any help!