Please Help ASAP Math Benchmark

I'm being volume of cylinder with 13 in. radius and 30 in height answer choices in pic

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

At the newest animated movie, for every 9 children, there are 4 adults. there are a total of 39 children and adults at the movie.