What this practice covers
These questions are drawn from past CIE 9708 papers and filtered to the interaction of demand and supply. You answer, you find out immediately whether you were right, and you get the reasoning for the correct option and for each distractor. Wrong answers go to a mistakes locker so you can come back to exactly those.
Practice is free. You need an account only so your progress and your mistakes are still there next time.
Start practising Paper 1 MCQs →
What examiners see students get wrong here
These are the errors that cost marks on the interaction of demand and supply, taken from our own topic notes. Read them before you practise and you will recognise the traps in the questions.
- Equilibrium means socially desirable. Wrong. Equilibrium only means quantity demanded equals quantity supplied.
- A shortage is shown by a vertical gap. Wrong. Shortages and surpluses are measured horizontally between quantities at a given price.
- A price below equilibrium creates a surplus. Wrong. It creates a shortage.
- A price above equilibrium creates a shortage. Wrong. It creates a surplus.
- An increase in demand means movement along demand. Wrong. It is a rightward shift of the demand curve.
- Increased supply raises equilibrium price. Wrong, ceteris paribus: price falls and quantity rises.
- Simultaneous shifts always give a definite price and quantity result. Wrong. One result may be ambiguous.
- Joint demand means substitutes. Wrong. Joint demand refers to complements.
Revise it first
If any of the above is unfamiliar, work through the notes before practising: The Interaction of Demand and Supply revision notes.