Help!

I'm writing the first book in a.series and my deadline is 6 days away. I've written 12,000 words but am aiming for at least 30,000. Writing 3,000 words daily is too much with all the homework I have. I will, however, have more time the last the last two days. How can I get it finished and is 30,000 words (150 pgs) long enough for a book meant for preteens, teens, and maybe young adults.