Combined average of two groups from group sizes and averages

CAT has tested this idea 3 times across 3 papers, from 2017 to 2025. 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 2025 Slot 3 · QA Q12	managers' 20% raise lifts overall average by 5%	A
CAT 2017 Slot 1 · QA Q14	boys and girls averages shift between exams	A
CAT 2022 Slot 3 · QA Q5	section averages 32 and 60; integer combined average	63

Part of Ratio, Mixtures & Averages (84 questions since 2017).