Help me answer these. Thanks.

2) Suppose that at time t = 0, an olive oil distributor found that the demand for olive oil, sold at $15 dollars a quart, was 500 quarts each month. At the same time, the price was going up at a rate of $0.50 per month, and the demand was also going up at a rate of 30 quarts per month due to increased advertising. How fast was the revenue increasing at time t = 0?

Note: The revenue function is given by R(t) = D(t)P(t) , where D(t) is the demand at time t, and P(t) is the price at time t.

5) According to work by the psychologist C. L. Hull, the strength of a habit is a function of the number of times the habit is repeated. If N is the number of repetitions and H(N) is the strength of the habit, then H(N) = 1000(1 - e^-kN) , where k is a constant.

(a) Find H'(N) if k = 0.1.

(b) Explain why H'(N) is always positive. What does this mean in the context of habits?