Derive the market demand and supply schedules by summing individual quantities at each price level.

Market supply is the sum of individual supplies from Joyce and John at each price.

$$\begin{align*} \text{At Price 50: } & 2 + 2 = 4 \\ \text{At Price 100: } & 3 + 3 = 6 \\ \text{At Price 150: } & 4 + 5 = 9 \\ \text{At Price 200: } & 5 + 7 = 12 \\ \text{At Price 250: } & 6 + 8 = 14 \\ \text{At Price 300: } & 7 + 9 = 16 \end{align*}$$

Market demand is the sum of individual demands from Mary and Agbor at each price.

$$\begin{align*} \text{At Price 50: } & 7 + 9 = 16 \\ \text{At Price 100: } & 6 + 8 = 14 \\ \text{At Price 150: } & 5 + 7 = 12 \\ \text{At Price 200: } & 4 + 5 = 9 \\ \text{At Price 250: } & 3 + 3 = 6 \\ \text{At Price 300: } & 2 + 2 = 4 \end{align*}$$

The combined market demand and supply schedules are:

Price (FCFA)	Market Supply (Units)	Market Demand (Units)
50	4	16
100	6	14
150	9	12
200	12	9
250	14	6
300	16	4

This table represents the market demand and supply schedules.