The demand curve for neccessity is usually

1. Analyze the question It asks about the usual shape of the demand curve for a necessity (a good like salt, bread, or garri that people need to live).

2. Explain the concept A demand curve shows the relationship between the price of a good and the quantity demanded, with other factors held constant. Under the law of demand, when price rises, quantity demanded falls, and when price falls, quantity demanded rises. This gives the curve a downward slope from left to right, which is called a negative slope.

Necessities have inelastic demand. People still need them even when prices change, so quantity demanded responds only slightly to price. This makes the curve steep, but it still slopes downward.

3. Work through the options

• A. Vertical: This is perfectly inelastic demand. It is a theoretical extreme and rarely occurs, even for necessities. Some people will still cut back a little if the price rises a lot, so it is not the usual shape.
• B. Backward bending: This describes the supply curve of labour, not a demand curve for goods.
• C. Horizontal: This is perfectly elastic demand. It applies to a firm in perfect competition, not to necessities.
• D. Negatively sloped: This follows the law of demand. Necessities have a steep negative slope because demand is inelastic.

4. Answer The correct option is D. negatively sloped.

5. Exam tip Remember that almost every normal demand curve slopes downward. Necessities are just steeper because demand is inelastic, and luxuries are flatter because demand is elastic. Be careful with "vertical", which is only the extreme case. WAEC usually wants the general rule, which is the negative slope.