Foundation
USE WHEN
Different items have different profit/loss percentages and cost weights, or markup/discount chains appear.
BEST METHOD
Cost-Weight Method
TARGET
90–120 sec
MASTERY
not started
Different items have different profit/loss percentages and cost weights, or markup/discount chains appear.
Overall profit/loss is based on total cost, not average of individual percentages.
When CP ratio is known, use ratio units as cost weights.
Take cost ratio as actual cost units and compute total SP and total CP.
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 2023 slot 1: same selling price with 20% profit and 10% loss. multiple 2024–2025 cat questions also mix markup, discount and profit.