This are all my attached questions that I don't quite get

Question 3. Find the interval(s) on which the following function is decreasing: f(:r:) = v3 21324-1 Question 4. The number of a certain type of bacteria increases exponentially. There are 60 present at an initial time and 180 present 2 hours later. How many bacteria will there be after 3 hours? Question 7. (10 points) At a price of 90 dollars for a trip, a rafting company sells 300 trips per day. Every 10 dollar decrease in price causes an additional 50 trips to be sold. The cost to the company is 700 dollars per day plus 30 dollars per customer. I Let :1: be the number of trips per day. Find a formula in terms of :1: for the total prot per day. 0 Find the price that maximizes the company's prot per clay. Be sure to explain why your answer is an absolute maximum. Question 1. Suppose that the demand function for a product is given by p = :1:2 6:1:+48. What is the elasticity of demand when a: = 3? Is demand elastic or inelastic? I \f