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3.8.E: Exercises

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    157592
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    3.8 Exercises

    Exercise \(\PageIndex{1}\)

    The demand and supply functions for a certain product are given by \(p = 150 - .5q\) and \(p = .002q^2+1.5\), where \(p\) is in dollars and \(q\) is the number of items.

    (a) Which is the demand function?

    (b) Find the equilibrium price and quantity

    (c) Find the total gains from trade at the equilibrium price.

    Exercise \(\PageIndex{2}\)

    Still thinking about the product from Exercise 1, with its demand and supply functions, suppose the price is set artificially at $70 (which is above the equilibrium price).

    (a) Find the quantity supplied and the quantity demanded at this price.

    (b) Compute the consumer surplus at this price, using the quantity demanded.

    (c) Compute the producer surplus at this price, using the quantity demanded (why?).

    (d) Find the total gains from trade at this price.

    (e) What do you observe?

    Exercise \(\PageIndex{3}\)

    When the price of a certain product is $40, 25 items can be sold. When the price of the same product costs $20, 185 items can be sold. On the other hand, when the price of this product is $40, 200 items will be produced. But when the price of this product is $20, only 100 items will be produced. Use this information to find supply and demand functions (assume for simplicity that the functions are linear), and compute the consumer and producer surplus at the equilibrium price.

    Exercise \(\PageIndex{4}\)

    Find the present and future values of a continuous income stream of $5000 per year for 12 years if money can earn 1.3% annual interest compounded continuously.

    Exercise \(\PageIndex{5}\)

    Find the present value of a continuous income stream of $40,000 per year for 35 years if money can earn

    (a) 0.8% annual interest, compounded continuously,

    (b) 2.5% annual interest, compounded continuously,

    (c) 4.5% annual interest, compounded continuously.

    Exercise \(\PageIndex{6}\)

    Find the present value of a continuous income stream \(F(t) = 20+t\), where \(t\) is in years and \(F\) is in tens of thousands of dollars per year, for 10 years, if money can earn 2% annual interest, compounded continuously.

    Exercise \(\PageIndex{7}\)

    Find the present value of a continuous income stream \(F(t) = 12+0.3t^t\), where \(t\) is in years and \(F\) is in thousands of dollars per year, for 8 years, if money can earn 3.7% annual interest, compounded continuously.

    Exercise \(\PageIndex{8}\)

    Find the future value of a continuous income stream \(F(t) = 8500+ \sqrt{640t+100}\), where \(t\) is in years and \(F\) is in dollars per year, for 15 years, if money can earn 6% annual interest, compounded continuously.

    Exercise \(\PageIndex{9}\)

    A business is expected to generate income at a continuous rate of $25,000 per year for the next eight years. Money can earn 3.4% annual interest, compounded continuously. The business is for sale for $153,000. Is this a good deal?


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