WASSCE Economics · Paper 1 style

Costs

One sample question with the full working. 2 more in the app, with instant feedback and repair sessions for the traps below.

Total cost is fixed cost plus

Amarginal cost
Baverage cost
Cvariable cost
Dprofit

Show the answer and working

Answer: C

TC = FC + VC.

Trap A Confuses cost concepts: TC = TFC + TVC. AC = TC/Q. MC = ΔTC/ΔQ. Fixed costs do not change with output.

Trap B Applies the rule for the opposite case: Before answering, name the case in the stem (inelastic? price floor ABOVE equilibrium? point INSIDE the PPC?) and recall the rule for that case only.

Trap D Stops at a different economic quantity: Underline what the question asks for and check the final number is THAT quantity, not a step on the way.

Traps in Costs

Confuses cost concepts
TC = TFC + TVC. AC = TC/Q. MC = ΔTC/ΔQ. Fixed costs do not change with output.
Applies the rule for the opposite case
Before answering, name the case in the stem (inelastic? price floor ABOVE equilibrium? point INSIDE the PPC?) and recall the rule for that case only.
Stops at a different economic quantity
Underline what the question asks for and check the final number is THAT quantity, not a step on the way.
Uses the wrong arithmetic operation
Write the definition in words first (TR = price × quantity; ATC = TC ÷ Q) and only then put in numbers. Check units: totals and averages cannot be added.
Turns the formula upside down
Learn the formula with its meaning: elasticity = responsiveness of QUANTITY, so %ΔQ is on top; k = 1/MPS = 1/(1 − MPC).

Practise Costs (2 questions)Send to your class on WhatsApp