A supply curve slopes upwards from the left to the right indicating__________

1. Analyze the question The question asks what it means when a supply curve slopes upwards from left to right. It is about the shape of the curve and what that shape tells us.

2. Explain the concept The law of supply says that, other things being equal, when the price of a good rises, the quantity producers are willing to supply also rises. When the price falls, the quantity supplied falls. Price and quantity supplied move in the same direction.

On a graph, price is on the vertical axis and quantity on the horizontal axis. A direct relationship between the two gives a curve that rises from the bottom left to the top right. In mathematics, a line that rises like this has a positive slope.

3. Work through the options

• A. Negative slope: This is a curve that falls from left to right, like a demand curve. It is wrong.
• B. Positive slope: Price and quantity supplied rise together, so the curve slopes upward. This is correct.
• C. Backward-sloping supply curve: This bends back to the left at higher prices. A typical example is labour supply, where people work fewer hours once wages are very high. It is a special case and not what a plain upward slope means.
• D. Short-run supply curve: This is about the time period, not the slope. A curve can slope upward in both the short run and the long run, so the slope alone doesn't tell you this.

4. Answer The upward slope from left to right indicates a positive slope, which is option B.

5. Exam tip Remember this pair:

• Supply → Same direction → Positive slope (upward)
• Demand → Opposite directions → Negative slope (downward)

In JAMB, when you see "slopes upwards" together with "supply", think "positive slope" right away.