Attached are three calculusproblems. Please show all step by stepwork.

1. If the total revenue received from the sale of x items is given byR(x) = 30 ln(2x+1) While the total cost to produce x items is C(x) = x/2, find the following: (A) The marginal revenue (B) The profit function P(x) (C) The marginal profit when x = 60 (D) Interpret the results of part (c) **On part "C", be sure to find the marginal profit function before citing what the marginal profit at x = 60 is. **On part "D", write a complete sentence answer that tells the meaning of the number found in (C). 2. An epidemic is growing in a region according to the rate N'(t) = 100t/t^2+2 Where N(t) is the number of people infected after t days. (a) Find a formula for the number of people infected after t days, given that 37 people were infected at t = 0. (b) Use your answer from part (a) to find the number of people infected after 21 days. 3. Written Problem: A partner in an investment firm will use the present value of continuous money flow to determine the best offer for a real estate investment that promises to generate an income flow of $8,000 per year over the next six years. If the prevailing interest rate is 2%, will an offer of $45,000 be more than the present value or less than the present value, and by how much