Two successive percentage changes with related rates

CAT has tested this idea 3 times across 3 papers, from 2021 to 2024. Solve one, and the others are the same method with different numbers or wording, which is why repeated concepts are the most efficient thing to practise.

Question	What it asks	Answer
CAT 2024 Slot 3 · QA Q8	second hike twice the first; total 187.5%	C
CAT 2021 Slot 2 · QA Q18	loss then gain five times as large; net 35%	C
CAT 2023 Slot 3 · QA Q10	population falls y%, rises x%, x − y = 10	D

Part of Percentages & Profit-Loss (46 questions since 2017).