Foundation
USE WHEN
A quantity undergoes two or more percentage changes one after another.
BEST METHOD
Multiplier Chain
TARGET
60–90 sec
MASTERY
not started
A quantity undergoes two or more percentage changes one after another.
Each change acts on the updated value, so multiply change factors.
Multiplier method is safer: final/original = ∏(1±r/100).
Write 1.20 × 0.90 × 1.10 rather than using the net-percent formula repeatedly.
Timed drill
Identify the base or invariant before you calculate.
Attempt first · Standard Example
Attempt first · CAT-Level Example
3-level practice ladder
Foundation
CAT Standard
Advanced / Hybrid
cat 2024 slot 3: two successive salary increments, with the second percentage twice the first.