Question 1: An item originally costs $50. Its price increases to $60. What is the percentage change?

Answer: 20

Question 2: A school had 200 students last year. This year, it has 180 students. Find the percentage change in student numbers.

Answer: -10

Question 3: The population of a town was 10,000. It increased to 10,500. Calculate the percentage change in population.

Answer: 5

Question 1: A car's value was $8,000 last year. This year, it depreciated to $6,400. Find the percentage change in value. Explain whether it is an increase or decrease and why.

Answer: 20% decrease

Question 2: A farmer's crop yield was 150 tons last harvest. This year, the yield is 165 tons. Calculate the percentage change and describe what this indicates about the crop yield.

Answer: 10% increase

Question 1: A shop reduces the price of a jacket from $80 to $64. What is the percentage discount offered?

Answer: 20

Question 2: A town's annual rainfall was 1200mm last year. This year, it was 1320mm. Find the percentage increase in rainfall.

Answer: 10

Question 1: A stock price fell from $150 to $120. What is the percentage change? If the stock then recovers to $135, what is the new percentage change from the original price? Show your calculations.

Answer: {"final_change":"-10","initial_change":"-20"}

Question 2: A company's profit increased from $50,000 to $70,000. Later, it decreased to $65,000. Calculate the percentage increase and decrease in profit. Which change is larger in percentage terms?

Answer: {"decrease":"7.14","increase":"40","which_larger":"Increase"}

Question 1: A bicycle's price increased from $200 to $250. A student calculates the percentage increase as 50%. Find the mistake and correct it.

Answer: The correct percentage increase is 25%. The mistake was using 50% instead of ((250-200)/200) x 100.

Question 2: A factory's output decreased from 500 units to 400 units. A student says the percentage change is -25%. Is this correct? If not, correct the mistake.

Answer: Yes, the calculation is correct: ((400-500)/500) x 100 = -20%. The mistake was in the percentage value, which should be -20%.