The amount $180 is what percent greater than $135

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?

I’m really confused and need to learn this

The complement of an angle is one-sixth the measure of the supplement of the angle. what is the measure of the complement angle?