Foundation

USE WHEN
Two or more people/groups have incomes/expenditures in a ratio and percentage changes alter the ratio.
BEST METHOD
Ratio × Savings Share Method
TARGET
90–120 sec
MASTERY
not started
Two or more people/groups have incomes/expenditures in a ratio and percentage changes alter the ratio.
Convert ratio units into algebraic bases, then apply the percentage multipliers.
Keep ratio units symbolic unless a total/absolute amount is required.
Compute savings units directly from income ratio and savings percentages.
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 1: incomes in ratio 8:6:5, different rent percentages, later income increases with fixed rent.