Will give crown for the RIGHT answer please do not mess around or give me weird links

Question and answers are in the attached picture. you so much in advance.

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

The collection of beautiful oil paintings currently on display at an art gallery well defined; set not well defined; not a set