Attempt the question, check the explanation, and continue with similar questions to build confidence before exams.
3 is a percentage, 4 is a fixed cost
3 is cost per unit x, 4 is cost per unit y
4 is a profit, 3 is a loss
3 is a quantity, 4 is a discount
Continue with nearby questions to strengthen the same chapter concept while you still have the context fresh in mind.