Question

Three individuals, Mary, Jack and Helen, make up the total demand for donuts per month in a particular market.

Mary’s demand curve is 5P = 5000 – 1.25QM. Jack’s demand curve for donuts is given by P = 1000 – 0.5QJ.
Helen’s demand curve is given by QH = 2000 – 2P. The market demand curve would be:

Answer 1

The market demand curve can be obtained by adding the individual demand curves of Mary, Jack, and Helen. The market demand curve is QD = 8000 – 12P.

Step-by-step explanation:

The market demand curve can be obtained by adding the individual demand curves of Mary, Jack, and Helen. Given:

Mary’s demand curve: 5P = 5000 – 1.25QM

Jack’s demand curve: P = 1000 – 0.5QJ

Helen’s demand curve: QH = 2000 – 2P

To obtain the market demand curve, we need to sum the values of QM, QJ, and QH. However, since the equations are given in terms of P and Q, we need to convert them into the same variables. Let's solve each equation for Q, resulting in:

Mary’s demand equation: QM = 4000 – 8P

Jack’s demand equation: QJ = 2000 – 2P

Helen’s demand equation: QH = 2000 – 2P

Now, we can sum the three demand equations to obtain the market demand equation:

QD = QM + QJ + QH = (4000 – 8P) + (2000 – 2P) + (2000 – 2P)

QD = 8000 – 12P

So, the market demand curve is QD = 8000 – 12P.