Foundation

USE WHEN
Quantities are in a ratio, then one or more components change by percentages.
BEST METHOD
Ratio Units Method
TARGET
90–120 sec
MASTERY
not started
Quantities are in a ratio, then one or more components change by percentages.
Represent ratio terms as convenient base units, apply percentage multipliers, then simplify.
Do not calculate absolute values unless total is required.
Take ratio terms as 2x, 3x etc. and apply percentage changes before simplifying.
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
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